Improve performance on metadata computation (#12785)

In this PR:

## Improve recompute metadata cache performance. We are aiming for
~100ms

Deleting relationMetadata table and FKs pointing on it
Fetching indexMetadata and indexFieldMetadata in a separate query as
typeorm is suboptimizing

## Remove caching lock

As recomputing the metadata cache is lighter, we try to stop preventing
multiple concurrent computations. This also simplifies interfaces

## Introduce self recovery mecanisms to recompute cache automatically if
corrupted

Aka getFreshObjectMetadataMaps

## custom object resolver performance improvement:  1sec to 200ms

Double check queries and indexes used while creating a custom object
Remove the queries to db to use the cached objectMetadataMap

## reduce objectMetadataMaps to 500kb
<img width="222" alt="image"
src="https://github.com/user-attachments/assets/2370dc80-49b6-4b63-8d5e-30c5ebdaa062"
/>

We used to stored 3 fieldMetadataMaps (byId, byName, byJoinColumnName).
While this is great for devXP, this is not great for performances.
Using the same mecanisme as for objectMetadataMap: we only keep byIdMap
and introduce two otherMaps to idByName, idByJoinColumnName to make the
bridge

## Add dataloader on IndexMetadata (aka indexMetadataList in the API)

## Improve field resolver performances too

## Deprecate ClientConfig

packages/twenty-server/src/engine/metadata-modules/index-metadata/index-metadata.entity.ts

@@ -80,5 +80,5 @@ export class IndexMetadataEntity {
     default: IndexType.BTREE,
     nullable: false,
   })
-  indexType?: IndexType;
+  indexType: IndexType;
 }

packages/twenty-server/src/engine/metadata-modules/index-metadata/index-metadata.service.ts

@@ -106,7 +106,10 @@ export class IndexMetadataService {
 
   async recomputeIndexMetadataForObject(
     workspaceId: string,
-    updatedObjectMetadata: ObjectMetadataEntity,
+    updatedObjectMetadata: Pick<
+      ObjectMetadataEntity,
+      'nameSingular' | 'isCustom' | 'id'
+    >,
   ) {
     const indexesToRecompute = await this.indexMetadataRepository.find({
       where: {
@@ -232,7 +235,10 @@ export class IndexMetadataService {
 
   async createIndexRecomputeMigrations(
     workspaceId: string,
-    objectMetadata: ObjectMetadataEntity,
+    objectMetadata: Pick<
+      ObjectMetadataEntity,
+      'nameSingular' | 'isCustom' | 'id'
+    >,
     recomputedIndexes: {
       indexMetadata: IndexMetadataEntity;
       previousName: string;

packages/twenty-server/src/engine/metadata-modules/index-metadata/interfaces/index-field-metadata.interface.ts

@@ -8,4 +8,6 @@ export interface IndexFieldMetadataInterface {
   fieldMetadata: FieldMetadataInterface;
   indexMetadata: IndexMetadataInterface;
   order: number;
+  createdAt: Date;
+  updatedAt: Date;
 }

packages/twenty-server/src/engine/metadata-modules/index-metadata/interfaces/index-metadata.interface.ts

@@ -1,7 +1,14 @@
 import { IndexFieldMetadataInterface } from 'src/engine/metadata-modules/index-metadata/interfaces/index-field-metadata.interface';
 
+import { IndexType } from 'src/engine/metadata-modules/index-metadata/index-metadata.entity';
+
 export interface IndexMetadataInterface {
+  id: string;
   name: string;
   isUnique: boolean;
   indexFieldMetadatas: IndexFieldMetadataInterface[];
+  createdAt: Date;
+  updatedAt: Date;
+  indexWhereClause: string | null;
+  indexType: IndexType;
 }