fix(builder): fix loads for relation with lazy loading set to true

[kevin-lot]

fix loads for relation with lazy loading set to true and rework some tests to work with memory database (and not mocks)

The fix: https://github.com/RobinCK/typeorm-fixtures/pull/198/files#diff-a958cbc039c63bc97979da7c9fe89951b68123f8ffaf17b6cf4dde65532259bbR34 :)

[kevin-lot]

@RobinCK What do you think about this PR ? I would like to have your opinion ?

[RobinCK]

I like it, but it no longer looks like a unit test, but more like an integration test, as sqlite is used I approved pr since the integration test adds reliability

[kevin-lot]

"but it no longer looks like a unit test"

I'm going to try to mock of "create" method of repository. For now, I keep this PR in draft during my investigation.

[Chrisp1tv]

Hello @kevin-lot, any progress on this? 😄