(core) Change 'Clear ... column' menu options to 'Reset', and make resetting columns reset type too

Summary:
The renaming is to clarify that the operation is more of a schema change, than
a data update. In particular, this is to reduce confusion why it is allowed to
anyone having Structure permission in Access Rules.

The resetting of type is a separate but related cleanup. Changing type to Any
returns the column to initial state, letting it guess type from new data, and
making it easy to enter a formula. It applies also to the "Clear and reset"
option in the Creator Panel.

Test Plan: Updated tests, added a check for type changing to Any.

Reviewers: jarek

Reviewed By: jarek

Differential Revision: https://phab.getgrist.com/D3685

app/client/components/GristDoc.ts

@@ -790,11 +790,18 @@ export class GristDoc extends DisposableWithEvents {
   }
 
   // Turn the given columns into empty columns, losing any data stored in them.
-  public async clearColumns(colRefs: number[]): Promise<void> {
+  public async clearColumns(colRefs: number[], {keepType}: {keepType?: boolean} = {}): Promise<void> {
     await this.docModel.columns.sendTableAction(
       ['BulkUpdateRecord', colRefs, {
         isFormula: colRefs.map(f => true),
         formula: colRefs.map(f => ''),
+        ...(keepType ? {} : {
+          type: colRefs.map(f => 'Any'),
+          widgetOptions: colRefs.map(f => ''),
+          visibleCol: colRefs.map(f => null),
+          displayCol: colRefs.map(f => null),
+          rules: colRefs.map(f => null),
+        }),
         // Set recalc settings to defaults when emptying a column.
         recalcWhen: colRefs.map(f => RecalcWhen.DEFAULT),
         recalcDeps: colRefs.map(f => null),

app/client/components/Importer.ts

@@ -692,7 +692,7 @@ export class Importer extends DisposableWithEvents {
                                 return [
                                   menuItem(
                                     async () => {
-                                      await this._gristDoc.clearColumns([sourceColId]);
+                                      await this._gristDoc.clearColumns([sourceColId], {keepType: true});
                                       await this._updateImportDiff(info);
                                     },
                                     'Skip',