[core] Introduces some transforms for data masking

[plusplusjiajia]

Purpose

Introduces four new Transform implementations for data masking:

1. HashTransform: Masks string columns by hashing with configurable algorithm (default SHA-256) and optional salt
2. PartialMaskTransform: Masks the middle part of string
3. NullTransform: Always returns null for the input field
4. DefaultValueTransform: Returns the default value based on the field's data type

[JingsongLi]

What these transforms refer from?

[plusplusjiajia]

What these transforms refer from?

These transforms reference the implementations of ranger data filter and snowflake mask function.
https://github.com/apache/ranger/blob/master/agents-common/src/main/resources/service-defs/ranger-servicedef-trino.json#L269
https://docs.snowflake.com/en/user-guide/security-column-intro
https://docs.snowflake.com/en/sql-reference/functions/sha2
https://docs.snowflake.com/en/sql-reference/functions/regexp_replace

[JingsongLi]

@plusplusjiajia When I look at Ranger, these functions seem to be more closely aligned with the SQL standard, such as to_hex, regexp_replace, and so on.

We have two options:

1. If we decide using standard SQL functions, which seems to require the ability to nest.
2. If we provide mask functions, we need to adopt a name that is more closely related to Mask, such as MASK_HASH instead of Hash.

[plusplusjiajia]

@plusplusjiajia When I look at Ranger, these functions seem to be more closely aligned with the SQL standard, such as to_hex, regexp_replace, and so on.

We have two options:

1. If we decide using standard SQL functions, which seems to require the ability to nest.
2. If we provide mask functions, we need to adopt a name that is more closely related to Mask, such as MASK_HASH instead of Hash.
   That's a good question, seems like we can consider it after supporting column masking.