[CHORE] Avoid isDefined duplicated reference, move it to twenty-shared (#9967)

# Introduction
Avoid having multiple `isDefined` definition across our pacakges
Also avoid importing `isDefined` from `twenty-ui` which exposes a huge
barrel for a such little util function

## In a nutshell
Removed own `isDefined.ts` definition from `twenty-ui` `twenty-front`
and `twenty-server` to move it to `twenty-shared`.
Updated imports for each packages, and added explicit dependencies to
`twenty-shared` if not already in place

Related PR https://github.com/twentyhq/twenty/pull/9941

packages/twenty-shared/src/index.ts

@@ -6,6 +6,6 @@ export * from './types/ConnectedAccountProvider';
 export * from './types/FieldMetadataType';
 export * from './utils/fieldMetadata/isFieldMetadataDateKind';
 export * from './utils/image/getImageAbsoluteURI';
+export * from './utils/isDefined';
 export * from './utils/strings';
 export * from './workspace';
-

packages/twenty-shared/src/utils/__tests__/isDefined.test.ts

@@ -0,0 +1,14 @@
+import { isDefined } from '../isDefined';
+describe('isDefined', () => {
+  it('returns true if value is not undefined nor null', () => {
+    expect(isDefined('')).toBe(true);
+  });
+
+  it('returns false if value is null', () => {
+    expect(isDefined(null)).toBe(false);
+  });
+
+  it('returns false if value is undefined', () => {
+    expect(isDefined(undefined)).toBe(false);
+  });
+});

packages/twenty-shared/src/utils/isDefined.ts

@@ -0,0 +1,4 @@
+import { isNull, isUndefined } from '@sniptt/guards';
+
+export const isDefined = <T>(value: T | null | undefined): value is T =>
+  !isUndefined(value) && !isNull(value);