[Feature] Better parsing of indexing SQL statements

Description

Currently we parse indexing SQL statements with our own homegrown parser. It needs to be updated in order to support the new kinds of indexes. Discussion here shows some of deficiencies. In particular the fn is_same_kind_columns in index.rs has to jump through some hoops in order to compare if the two expressions are "kind of same". For instance BlockRangeLower and Unknown("lower(block_range) int4_minmax_multi_ops)"). Also the test generate_ddl() has a commented out line in the mock_thing_index_list for the same reason.

Related to this is generator of SQL statements that is not perfectly sanitising it's output, somewhat addressed in this.

One approach would be to extend the current parser to handle those cases. Other would be to use sqlparser or similar.

Are you aware of any blockers that must be resolved before implementing this feature? If so, which? Link to any relevant GitHub issues.

No response

Some information to help us out

• Tick this box if you plan on implementing this feature yourself.
• I have searched the issue tracker to make sure this issue is not a duplicate.

index.rs の fn is_same_kind_columns と generate_ddl() のテストから始め、mock_thing_index_list にあるコメントアウトされたエントリも確認してください。リンク先の議論を確認し、現在のパーサーを拡張する場合と sqlparser または同様のパーサーを使用する場合を比較してください。新しいインデックス種別と BlockRangeLower のような式が、現在の回避策なしでパースおよび比較され、SQL 出力のサニタイズが適切に対処されれば完了です。