Support for PK changes from signed int to unsigned bigint

## Feature Request

**Is your feature request related to a problem? Please describe:**

A table is created with `INT` (signed). Then the volume of the data changes. Changing it to `BIGINT` might help a bit but eventually changing it to `BIGINT UNSIGNED` is needed.

This can be seen as a sub-issue of #18090

**Describe the feature you'd like:**

Allow this to work:
```sql
CREATE TABLE t (id INT, PRIMARY KEY (id));
ALTER TABLE t MODIFY COLUMN id BIGINT UNSIGNED;
```

**Describe alternatives you've considered:**

Something like this might be possible:

```sql
CREATE TABLE t2 (id BIGINT UNSIGNED, PRIMARY KEY (id));
INSERT INTO t2 SELECT * FROM t;
RENAME TABLE t TO t_old, t2 TO t;
DROP TABLE t_old;
```

However:
- This would likely cause and/or need downtime for the application
- This is not very efficient
- This would cause a big stream of data on TiCDC
- This needs TiDB specific handling of this change (not MySQL Compatible behavior)
- This either needs the `BATCH` statement or external tools for larger tables, adding operational overhead.
- This needs a lot of time.

Another option:
```sql
ALTER TABLE t DROP PRIMARY KEY;
ALTER TABLE t MODIFY COLUMN id BIGINT UNSIGNED;
ALTER TABLE t ADD PRIMARY KEY(id);
```

However:
- This only works for `NONCLUSTERED` tables, which isn't the default
- This leaves a gap in which PK's are not enforced.
- Doing these 3 operations in a single statement isn't supported by TiDB.

**Teachability, Documentation, Adoption, Migration Strategy:**

1. New negative values should be rejected
2. Then the table contents should be checked for negative values
3. Then the change should be made. This should be a metadata only change if possible.
4. Then values bigger than the max-signed value should be allowed.