[Enhancement] Ignore union type tag when converting avro to json (backport #52973)

Why I'm doing:

schema:

 {
    "type": "record",
    "name": "User",
    "fields": [
        {"name": "id", "type": "int"},
        {"name": "name", "type": "string"},
        {"name": "email", "type": ["null",
                                   {
                                       "type": "record",
                                       "name": "email2",
                                       "fields": [
                                           {
                                               "name": "x",
                                               "type" : ["null", "int"]
                                           },
                                           {
                                               "name": "y",
                                               "type": ["null", "string"]
                                           }
                                       ]
                                   }
                                  ]
         }
    ]
 }

avro avro_value_to_json result: {"id": 1, "name": "Alice", "email": {"email2": {"x": {"int": 1}, "y": {"string": "alice@example.com"}}}}

What I'm doing:

add a new function to convert avro values to JSON strings while ignoring union type tags. {"id":1,"name":"Alice","email":{"x":1,"y":"alice@example.com"}}

add a new config avro_ignore_union_type_tag and modify existing functions to use this new conversion method based on the config.

Fixes #issue

What type of PR is this:

[ ] BugFix
[ ] Feature
[x] Enhancement
[ ] Refactor
[ ] UT
[ ] Doc
[ ] Tool

Does this PR entail a change in behavior?

[ ] Yes, this PR will result in a change in behavior.
[x] No, this PR will not result in a change in behavior.

If yes, please specify the type of change:

[ ] Interface/UI changes: syntax, type conversion, expression evaluation, display information
[ ] Parameter changes: default values, similar parameters but with different default values
[ ] Policy changes: use new policy to replace old one, functionality automatically enabled
[ ] Feature removed
[ ] Miscellaneous: upgrade & downgrade compatibility, etc.

Checklist:

[x] I have added test cases for my bug fix or my new feature
[ ] This pr needs user documentation (for new or modified features or behaviors)
- [ ] I have added documentation for my new feature or new function
[x] This is a backport pr

Bugfix cherry-pick branch check:

[x] I have checked the version labels which the pr will be auto-backported to the target branch

[x] 3.4
[x] 3.3
[ ] 3.2
[ ] 3.1
[ ] 3.0

[ ] 2.5

This is an automatic backport of pull request #52973 done by Mergify.