Move view in metadata-modules/ and create atomic folder + module for each view entity (#14990)

# Introduction
Preparing view-filter and view-group introduction in v2 core engine
Moving view from `core-modules` to `metadata-modules`

## What happened

### Created dedicated modules for each view entity:
- ViewFieldModule
- ViewFilterModule
- ViewFilterGroupModule
- ViewGroupModule
- ViewSortModule

### Each module is now completely independent with its own:
- Controller
- Resolver
- Service
- Entity

### Created dedicated abstraction metadata module folder for:
- flat-view-field
- flat-view

### Dependencies 
- Eleminated circular dep on ViewModule to all others ones
- Granular import not importing the whole viewModule anymore everywhere


close https://github.com/twentyhq/core-team-issues/issues/1703

packages/twenty-server/src/engine/metadata-modules/view/enums/view-calendar-layout.enum.ts

@@ -0,0 +1,5 @@
+export enum ViewCalendarLayout {
+  DAY = 'DAY',
+  WEEK = 'WEEK',
+  MONTH = 'MONTH',
+}

packages/twenty-server/src/engine/metadata-modules/view/enums/view-key.enum.ts

@@ -0,0 +1,3 @@
+export enum ViewKey {
+  INDEX = 'INDEX',
+}

packages/twenty-server/src/engine/metadata-modules/view/enums/view-open-record-in.ts

@@ -0,0 +1,4 @@
+export enum ViewOpenRecordIn {
+  SIDE_PANEL = 'SIDE_PANEL',
+  RECORD_PAGE = 'RECORD_PAGE',
+}

packages/twenty-server/src/engine/metadata-modules/view/enums/view-type.enum.ts

@@ -0,0 +1,5 @@
+export enum ViewType {
+  TABLE = 'TABLE',
+  KANBAN = 'KANBAN',
+  CALENDAR = 'CALENDAR',
+}