BP: add builtin processor part#1

[maha-mstfa]

Description

three builtin processors: https://github.com/ConduitIO/conduit/issues/1290 field.set field.subset.exclude field.rename field.convert filter docs for processors: https://github.com/ConduitIO/conduit/blob/main/docs/design-documents/20231117-better-processors.md#processors

Related to #1290

Quick checks:

• [x] I have followed the Code Guidelines.
• [x] There is no other pull request for the same update/change.
• [x] I have written unit tests.
• [x] I have made sure that the PR is of reasonable size and can be easily reviewed.