feat: add MariaDB parser to monorepo

[h3n4l]

Summary

• Migrates the MariaDB parser from standalone mariadb-parser repository
• Adds test coverage with 22 SQL example files
• Updates CI workflow to include mariadb in test matrix
• All tests passing successfully

Changes

• Added MariaDB grammar files (MariaDBLexer.g4, MariaDBParser.g4)
• Added 22 test examples covering various SQL statements
• Created Makefile for building and testing the parser
• Updated package names from parser to mariadb
• Updated import paths to github.com/bytebase/parser/mariadb
• Updated .github/workflows/tests.yml to include mariadb parser
• Generated parser files using ANTLR 4 with Go target

Test plan

• All 22 MariaDB parser tests passing
• Parser generation successful with ANTLR 4
• CI workflow updated to include mariadb parser
• Package names and imports updated correctly

🤖 Generated with Claude Code