fix(schema): keep custom functions on nested fields

[nitin-remote]

Fixes 2 issues for nested form fields

1. The path not getting transformed correctly for nested field.
2. Passed functions under modify getting lost during updating field configs

Internal issue | Internal MR E2E tests

[sandrina-p]

Hi @nitin-remote! Let us know when you add the tests, then you can add me, @lukad and @dragidavid as reviewers :)

[sandrina-p]

Approved, good to go! I'll release it in a minute

[sandrina-p]

@nitin-remote there you go, @remoteoss/[email protected] released!