feat(transactional): allows injecting custom providers into custom transaction adapter

[Anurag9977]

• Updated the TransactionalAdapter interface and the TransactionalOptionsAdapterFactory type with optional properties custom provider tokens and custom providers respectively.
• Updated the ClsPluginTransactional class to include extraProviderTokens into the TransactionalAdapterOptions provider.
• Updated CustomAdapter docs.

relates to #444

[Papooch]

Hi, thank you for the PR. I made some maintenance over the weekend, so could you please rebase your branch on top of the current main?

Also, before we merge this feature, please add some tests that cover it. If you aren't sure how to approach it, let me know and I'll try to give you some guidance.

[Anurag9977]

Hi, Sure. I'll rebase and update the PR.
Regarding tests, I believe we need to add a custom transactional adapter test but I would appreciate some pointers or maybe any existing test I can look at. That would be helpful.