MDEV-34317 Implement RECORD type

[iqbal-rsec]

Implement DECLARE TYPE type_name IS RECORD (..) with scalar members in
stored routines and anonymous blocks

• The Jira issue number for this PR is: MDEV-34317

Description

The patch implements RECORD type with the grammar DECLARE TYPE type_name IS RECORD (..) for sql_mode=oracle; for usage in anonymous blocks and stored routines with scalar fields.

New error code has been introduced ER_SP_DUP_DECL which is thrown when the same identifier for a RECORD is used twice or more (duplicate declaration of a RECORD TYPE).

Limitations: please see MDEV-34317
Additionally support for RECORD type declaration in PACKAGEs, stored routine parameters are out of scope of this ticket, but is required by my org (please advice if new ticket is required).

Release Notes

Introduce support for RECORD collection type based on the Oracle DB grammar with scalar fields for sql_mode=oracle;.

I believe a new documentation page is needed for this.

How can this PR be tested?

mysql-test/mtr sp-record

Basing the PR against the correct MariaDB version

• This is a new feature or a refactoring, and the PR is based against the main branch.
• This is a bug fix, and the PR is based against the earliest maintained branch in which the bug can be reproduced.

PR quality check

• I checked the CODING_STANDARDS.md file and my PR conforms to this where appropriate.
• For any trivial modifications to the PR, I am ok with the reviewer making the changes themselves.

[CLAassistant]

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