[Refactoring]: Migrate bit-pattern and encoding integer parameters

## Parent

- #28893

## Dependency

Depends on the shared contract delivered by the binding-layer foundation subtask.

## Scope

Migrate bit-pattern and encoding consumers while preserving their public source domains:

- HEX
- CHAR
- MAKE_SET
- EXPORT_SET
- CONV

Preserve BIN/OCT and CONV radix-string semantics, text bit range, ENUM ordinal behavior, and the existing MORPC v74 HEX compatibility path.

## Acceptance criteria

- Signed numeric, unsigned/BIT, and text bit-pattern domains remain distinct.
- New binding never routes unchecked REAL/DECIMAL values through a bit-pattern adapter.
- Existing HEX catalog migration and legacy execution identities remain valid.
- Public SQL and prepared tests cover large unsigned values, negative text prefixes, ENUM, NULL, and overflow.
- No new coercion semantics or protocol identity is introduced.