[SalesForce] lwc: sfdx unable to retrieve lwc files

Normal HTML applies here; you can just remove the element:

const chartContainer = this.template.querySelector('div.chart');
while(chartContainer.firstChild) {
  chartContainer.removeChild(chartContainer.firstChild);
}
chartContainer.appendChild(this.canvas);

Or, instead of dumping the old canvas, you could clear the canvas and draw anew.

const context = this.canvas.getContext('2d');
context.clearRect(0, 0, this.canvas.width, this.canvas.height);

You're probably missing out type attribute in the columns for the formula field. Since it's a formula-text field. The default text column is applied.

You need to add a type attribute to the columns for that field that should be like,

  columns = [
    // standard text column
    { label: "Text Column", fieldName: "textCol", wrapText: true },
    {
      label: "Text Column",
      fieldName: "richField",
      type: "richText",
      wrapText: true,
    },
    {
      label: "Rich Text",
      fieldName: "richTextCol__c",
      type: "richText", //specify a type attribute here 
      wrapText: true,
    },
  ];

You can see a live demo here.

Once you get columns from apex. You need to change the type attribute before assigning it to the columns attribute.

  connectedCallback() {
    result.map((col) => {
      if (col.fieldName === YOUR_RICH_TEXT_FIELD) {
        return (col.type = "richText");
      }
    });
   this.columns = result;
  }

Apex Class

public with sharing class ICRM_DynamicRelatedRecordsList_Ctrlr {

    @AuraEnabled (Cacheable= true)
    public static String getIconName(String objectName) {
        String u;
        List<Schema.DescribeTabSetResult> tabSetDesc = Schema.describeTabs();
        List<Schema.DescribeTabResult> tabDesc = new List<Schema.DescribeTabResult>();
        List<Schema.DescribeIconResult> iconDesc = new List<Schema.DescribeIconResult>();

        for (Schema.DescribeTabSetResult tsr : tabSetDesc) {
            tabDesc.addAll(tsr.getTabs());
        }

        for (Schema.DescribeTabResult tr : tabDesc) {
            if (objectName == tr.getSobjectName()) {
                if (tr.isCustom() == true) {
                    iconDesc.addAll(tr.getIcons());
                } else {
                    u = 'standard:' + objectName.toLowerCase();
                }
            }
        }
        for (Schema.DescribeIconResult ir : iconDesc) {
            if (ir.getContentType() == 'image/svg+xml') {
                u = 'custom:' + ir.getUrl().substringBetween('custom/', '.svg').substringBefore('_');
                break;
            }
        }
        return u;
    }

    @AuraEnabled (Cacheable= true)
    public static String getObjectLabel(String sobjectApiName) {
        Schema.SObjectType sobjectType = Schema.getGlobalDescribe().get(sobjectApiName);
        Schema.DescribeSObjectResult sobjectDescribe = sobjectType.getDescribe();
        return sobjectDescribe.getLabelPlural();
    }

    @AuraEnabled (Cacheable= true)
    public static ColumnAndDataWrapper getFieldSet(String sObjectName, String listOfFields, Id recordId, String relationshipField, Integer recordsToDisplay) {
        ColumnAndDataWrapper cdw = new ColumnAndDataWrapper();
        List<Columns> columns = new List<Columns>();
        String fieldsToFetch = '';

        Map<String, Schema.SObjectType> gd = Schema.getGlobalDescribe();
        Schema.SObjectType ctype = gd.get(sObjectName);
        Map<String, Schema.SObjectField> fmap = ctype.getDescribe().fields.getMap();

        List<String> fieldList = listOfFields.replaceAll(' ','').split(',');

        // Generating a list of columns
        for (String f : fieldList) {
            if (f == 'Name') {
                // Uncomment and replace to allow go to record by clicking name
                // columns.add(new Columns(fmap.get(f).getDescribe().getLabel(), 'linkName', 'url'));
                columns.add(new Columns(fmap.get(f).getDescribe().getLabel(), 'Name', 'text'));
            } else {
                columns.add(new Columns(fmap.get(f).getDescribe().getLabel(), f, String.valueOf(fmap.get(f).getDescribe().getType()).toLowerCase()));
            }
            if (fieldsToFetch != '') {
                fieldsToFetch += ',';
            }
            fieldsToFetch += f;
        }

        // Get the records of requested object
        List<SObject> listData;
        if (recordsToDisplay == null) {
            listData = Database.query('SELECT Id, ' + fieldsToFetch + ' FROM ' + sObjectName + ' WHERE ' + relationshipField + ' = :recordId ');
        } else if (recordsToDisplay != null && recordsToDisplay > 0) {
            listData = Database.query('SELECT Id, ' + fieldsToFetch + ' FROM ' + sObjectName + ' WHERE ' + relationshipField + ' = :recordId LIMIT ' + recordsToDisplay);
        }
        cdw.columns = columns;
        cdw.listData = listData;
        return cdw;
    }

    public class Columns {
        @AuraEnabled public String label;
        @AuraEnabled public String fieldName;
        @AuraEnabled public String type;
        public Columns(String label, String fieldName, String type) {
            this.label = label;
            this.fieldName = fieldName;
            this.type = type;
        }
    }

    public class ColumnAndDataWrapper {
        @AuraEnabled public List<Columns> columns;
        @AuraEnabled public List<SObject> listData;
    }

}