fix(provider): return proper repository

[dineshsalunke]

check if the entity has tree metadata and return a tree repository if it exists

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

Currently the providers don't return a TreeRepository for tree entities.

What is the new behavior?

Now the provider will create and return a tree repository for tree entities

Does this PR introduce a breaking change?

• Yes
• No

Other information

[dineshsalunke]

@kamilmysliwiec any update ?

[Kisama]

I am waiting this PR is merged

[dineshsalunke]

@micalevisk @kamilmysliwiec any plans on merging this PR ?

[micalevisk]

you can use patch-package until the merge

I don't have permissions to merge PRs

[dineshsalunke]

@micalevisk we are already using patch-package for this, but that's not the ideal thing

[dineshsalunke]

@kamilmysliwiec any idea if this can be merged or not ?

[kamilmysliwiec]

LGTM