fix(plan): support enum and prefix text indexes

[ck89119]

What type of PR is this?

• API-change
• BUG
• Improvement
• Documentation
• Feature
• Test and CI
• Code Refactoring

Which issue(s) this PR fixes:

Fixes #24740
Fixes #24729

What this PR does / why we need it:

• Allows ENUM columns in secondary, unique, and composite indexes while keeping ENUM primary keys rejected.
• Allows TEXT/BLOB prefix indexes and keeps plain TEXT/BLOB indexes rejected.
• Persists index prefix lengths in index metadata and applies prefix expressions during index backfill, insert, unique dedup, and lock-key generation.
• Adds focused unit coverage and BVT cases for ENUM indexes and TEXT/BLOB prefix indexes.

Validation:

• go test ./pkg/sql/plan -run 'TestBuildIndexAllowsEnumAndTextBlobPrefix|TestBuildIndexRejectsTextBlobPlainIndex' -count=1
• go test ./pkg/sql/compile -run 'TestGenInsertIndexTableSql_UsesPrefixExpression|TestBuildCreateUniqueIndexDuplicateCheckSQL' -count=1
• go test ./pkg/sql/colexec/preinsertunique ./pkg/sql/colexec/preinsertsecondaryindex -count=1
• ./run.sh -p /Users/LoveYY/Develop/matrixorigin/matrixone/.worktrees/issue-24740/test/distributed/cases/ddl/create_index.sql -g -n
• ./run.sh -p /Users/LoveYY/Develop/matrixorigin/matrixone/.worktrees/issue-24740/test/distributed/cases/dtype/enum.sql -g -n
• git diff --check
• make
• make static-check

[qodo-code-review]

Qodo reviews are paused for this user.

Troubleshooting steps vary by plan Learn more →

On a Teams plan?
Reviews resume once this user has a paid seat and their Git account is linked in Qodo.
Link Git account →

Using GitHub Enterprise Server, GitLab Self-Managed, or Bitbucket Data Center?
These require an Enterprise plan - Contact us
Contact us →