Fix flatFieldMetadata transpiler to fit real cache typing (#13529)

# Introduction
The cache is not accurately typed regarding the `fieldMetadataMaps` they
do not contain relations
In this way we:
- Created dedicated transpilation tools for cache manipulation
- Avoided recursivity in transpilation tools
- Fix and finalized the createMany fields metadata service v2
- Refactor the validator to handle validation :)

## What's next:
- Implem integration tests to make things run 🙃 
- migrate existing settings valdiation
- Finish the create object metadata service
- Handle update input transpilation and validation

packages/twenty-server/src/engine/utils/is-cached-field-metadata-of-type.util.ts

@@ -0,0 +1,14 @@
+import { FieldMetadataType } from 'twenty-shared/types';
+
+import { CachedFieldMetadataEntity } from 'src/engine/metadata-modules/types/cached-field-metadata-entity';
+
+export function isCachedFieldMetadataEntityOfType<
+  Field extends CachedFieldMetadataEntity<FieldMetadataType>,
+  Type extends FieldMetadataType,
+>(
+  fieldMetadata: Pick<Field, 'type'>,
+  type: Type,
+): fieldMetadata is CachedFieldMetadataEntity &
+  CachedFieldMetadataEntity<Type> {
+  return fieldMetadata.type === type;
+}