MariaDB index parser (`db_verify::getIndex()`) doesn't detect optional parts of `index_col_name` in `index_definition`

[Deltik]

Bug Description

In the MariaDB CREATE TABLE index_definition, the index_col_name could have an optional length and a sort order:

index_definition:
    {INDEX|KEY} [index_name] [index_type] (index_col_name,...) [index_option] ...
  {{{|}}} {FULLTEXT|SPATIAL} [INDEX|KEY] [index_name] (index_col_name,...) [index_option] ...
  {{{|}}} [CONSTRAINT [symbol]] PRIMARY KEY [index_type] (index_col_name,...) [index_option] ...
  {{{|}}} [CONSTRAINT [symbol]] UNIQUE [INDEX|KEY] [index_name] [index_type] (index_col_name,...) [index_option] ...
  {{{|}}} [CONSTRAINT [symbol]] FOREIGN KEY [index_name] (index_col_name,...) reference_definition

index_col_name:
    col_name [(length)] [ASC | DESC]

index_type:
    USING {BTREE | HASH | RTREE}

index_option:
    [ KEY_BLOCK_SIZE [=] value
  {{{|}}} index_type
  {{{|}}} WITH PARSER parser_name
  {{{|}}} COMMENT 'string'
  {{{|}}} CLUSTERING={YES| NO} ]
  [ IGNORED | NOT IGNORED ]

reference_definition:
    REFERENCES tbl_name (index_col_name,...)
      [MATCH FULL | MATCH PARTIAL | MATCH SIMPLE]
      [ON DELETE reference_option]
      [ON UPDATE reference_option]

reference_option:
    RESTRICT | CASCADE | SET NULL | NO ACTION

db_verify::getIndex() doesn't handle this possibility, leading to a database validity check failure despite the index actually existing.

How to Reproduce

/e107_admin/db.php?mode=verify_sql with MariaDB 10.6.14?

Expected Behavior

No check failure after auto-fixing all the failures