[Feature] Support function in paimon

[jerry-024]

Search before asking

• [x] I searched in the issues and found nothing similar.

Motivation

The defining function includes the parameter, output, and function body. The output result is a single value or a table. It is modeled after unity catalog，and it could support the following scenarios:

1. Support filtering or encrypting column in row: select decode_email(email) from user;
2. Support parameterized view: select filter_fruit_by_color('red');
3. Support use the function in AI.

Solution

Provide the ability to define function. PIP-31: Introduce Function

Anything else?

No response

Are you willing to submit a PR?

• [x] I'm willing to submit a PR!