feat: add PL/SQL parser to monorepo (#28)

This commit adds the Oracle PL/SQL parser (supporting Oracle 11g and 12c) from the standalone plsql-parser repository into the unified parser monorepo.

Changes:
- Added PL/SQL grammar files (PlSqlLexer.g4, PlSqlParser.g4)
- Added helper files (keywords.go, plsql_lexer_base.go, plsql_parser_base.go)
- Added test infrastructure with 338 example files and 32 sql-script examples
- Created Makefile for building and testing the parser
- Updated package names from 'parser' to 'plsql'
- Updated import paths to github.com/bytebase/parser/plsql
- Updated CI workflow to include plsql in the test matrix
- Generated parser files using ANTLR 4 with Go target
- All 370 tests passing successfully

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude <[email protected]>

Author: h3n4l

.github/workflows/tests.yml

@@ -34,7 +34,7 @@ jobs:
         id: set-matrix
         run: |
           # List of all available parsers
-          ALL_PARSERS="redshift postgresql cql snowflake tsql doris trino"
+          ALL_PARSERS="redshift postgresql cql snowflake tsql doris trino plsql"
           # Add more parsers here as they are added to the repository
           # ALL_PARSERS="redshift mysql postgresql"
 

plsql/Makefile

@@ -0,0 +1,7 @@
+all: build test
+
+build:
+	antlr -Dlanguage=Go -package plsql -visitor -o . PlSqlLexer.g4 PlSqlParser.g4
+
+test:
+	go test -v -run TestPLSQLParser