refactor: remove "core" naming from views and eliminate converter layer (#18667)

## Summary

- **Remove all "core" prefixes** from the views system — the
metadata-based storage migration is complete, so `CoreView`,
`coreViewsSelector`, `getCoreViews`, etc. are now just `View`,
`viewsSelector`, `getViews`
- **Eliminate the entire converter layer** (15 files, ~850 lines
deleted) — `convertCoreViewToView` and all sub-converters were either
no-ops or trivially adding `__typename` / mapping identical enum values.
Local enums now re-export from generated GraphQL types directly (single
source of truth)
- **Unify `View` and `ViewWithRelations`** into one type —
`ViewWithRelations` is now a type alias for `View`, selectors return
data directly without conversion

### Backend
- Rename `@ObjectType('CoreView')` → `@ObjectType('View')` (and all
sub-entities)
- Rename resolver methods: `getCoreViews` → `getViews`, `createCoreView`
→ `createView`, etc.
- Rename `FIND_ALL_CORE_VIEWS_GRAPHQL_OPERATION` →
`FIND_ALL_VIEWS_GRAPHQL_OPERATION`

### Frontend
- Delete 15 converter files (`convertGqlView*ToView*`,
`convertView*ToGql`, `convertViewWithRelationsToView`)
- Re-export `ViewType`, `ViewKey`, `ViewFilterGroupLogicalOperator` from
generated enums (no more duplicate enum definitions with different
casing)
- Replace `ViewOpenRecordInType` with `ViewOpenRecordIn` from generated
- Remove `__typename` from all local view sub-types
- Remove unused `variant` from `ViewFilter`, make `displayValue` and
`definition` optional
- Rename ~45 GraphQL query/mutation files and all selectors to drop
"core" prefix
- Delete unused `viewsWithRelationsSelector`

packages/twenty-front/src/modules/views/view-picker/components/ViewPickerCreateButton.tsx

@@ -57,7 +57,7 @@ export const ViewPickerCreateButton = () => {
   }
 
   if (
-    viewPickerType === ViewType.Kanban &&
+    viewPickerType === ViewType.KANBAN &&
     availableFieldsForGrouping.length === 0
   ) {
     return (
@@ -73,7 +73,7 @@ export const ViewPickerCreateButton = () => {
   }
 
   if (
-    viewPickerType === ViewType.Calendar &&
+    viewPickerType === ViewType.CALENDAR &&
     availableFieldsForCalendar.length === 0
   ) {
     return (
@@ -89,7 +89,7 @@ export const ViewPickerCreateButton = () => {
   }
 
   if (
-    viewPickerType !== ViewType.Kanban ||
+    viewPickerType !== ViewType.KANBAN ||
     viewPickerMainGroupByFieldMetadataId !== ''
   ) {
     return (
@@ -103,9 +103,9 @@ export const ViewPickerCreateButton = () => {
         justify="center"
         disabled={
           viewPickerIsPersisting ||
-          (viewPickerType === ViewType.Kanban &&
+          (viewPickerType === ViewType.KANBAN &&
             viewPickerMainGroupByFieldMetadataId === '') ||
-          (viewPickerType === ViewType.Calendar &&
+          (viewPickerType === ViewType.CALENDAR &&
             viewPickerCalendarFieldMetadataId === '')
         }
       />