[TEST] Covering useDeleteOne relations optimistic cache behavior (#10238)

## Introduction
Added coverage on the `useDeleteOneRecord` hooks, especially its
optimistic behavior feature.
Introduced a new testing tool `InMemoryTestingCacheInstance` that has
builtin very basic expectors in order to avoid future duplication when
covering others record hooks `update, create, destroy` etc etc

## Notes
Added few comments in this PR regarding some builtin functions I've
created around companies and people mocked object model and that I think
could be cool to spread and centralize within a dedicated "class
template"

Also put in light that unless I'm mistaken some tests are running on
`RecordNode` and not `RecordObject`

Took few directions on my own that as I always I would suggestion nor
remarks on them !

Let me know

## Misc
- Should we refactor `useDeleteOneRecord` tests to follow `eachTesting`
pattern ? => I feel like this is inappropriate as this hooks is already
high level, the only plus value would be less tests code despite
readability IMO

packages/twenty-front/src/testing/graphqlMocks.ts

@@ -14,7 +14,7 @@ import { mockedClientConfig } from '~/testing/mock-data/config';
 import { mockedFavoritesData } from '~/testing/mock-data/favorite';
 import { mockedFavoriteFoldersData } from '~/testing/mock-data/favorite-folders';
 import { mockedNotes } from '~/testing/mock-data/notes';
-import { getPeopleMock } from '~/testing/mock-data/people';
+import { getPeopleRecordConnectionMock } from '~/testing/mock-data/people';
 import { mockedRemoteTables } from '~/testing/mock-data/remote-tables';
 import { mockedUserData } from '~/testing/mock-data/users';
 import { mockedViewsData } from '~/testing/mock-data/views';
@@ -33,7 +33,7 @@ import {
 import { mockedRemoteServers } from './mock-data/remote-servers';
 import { mockedViewFieldsData } from './mock-data/view-fields';
 
-const peopleMock = getPeopleMock();
+const peopleMock = getPeopleRecordConnectionMock();
 const companiesMock = getCompaniesMock();
 const duplicateCompanyMock = getCompanyDuplicateMock();