[ES|QL] pull in multi-file grammars (#212430)

## Summary

Resolve #210518

Successful grammar update PR!
#212442

.buildkite/scripts/steps/esql_grammar_sync.sh

@@ -4,10 +4,13 @@ set -euo pipefail
 synchronize_lexer_grammar () {
   license_header="$1"
   source_file="$PARENT_DIR/elasticsearch/x-pack/plugin/esql/src/main/antlr/EsqlBaseLexer.g4"
+  source_lib_dir="$PARENT_DIR/elasticsearch/x-pack/plugin/esql/src/main/antlr/lexer"
   destination_file="./src/platform/packages/shared/kbn-esql-ast/src/antlr/esql_lexer.g4"
+  destination_lib_dir="./src/platform/packages/shared/kbn-esql-ast/src/antlr/lexer"
 
   # Copy the file
   cp "$source_file" "$destination_file"
+  cp -r "$source_lib_dir" "$destination_lib_dir"
 
   # Insert the license header
   temp_file=$(mktemp)
@@ -26,10 +29,13 @@ synchronize_lexer_grammar () {
 synchronize_parser_grammar () {
   license_header="$1"
   source_file="$PARENT_DIR/elasticsearch/x-pack/plugin/esql/src/main/antlr/EsqlBaseParser.g4"
+  source_lib_dir="$PARENT_DIR/elasticsearch/x-pack/plugin/esql/src/main/antlr/parser"
   destination_file="./src/platform/packages/shared/kbn-esql-ast/src/antlr/esql_parser.g4"
+  destination_lib_dir="./src/platform/packages/shared/kbn-esql-ast/src/antlr/parser"
 
   # Copy the file
   cp "$source_file" "$destination_file"
+  cp -r "$source_lib_dir" "$destination_lib_dir"
 
   # Insert the license header
   temp_file=$(mktemp)

src/platform/packages/shared/kbn-esql-ast/package.json

@@ -1,12 +1,14 @@
 {
-    "name": "@kbn/esql-ast",
-    "version": "1.0.0",
-    "private": true,
-    "license": "Elastic License 2.0 OR AGPL-3.0-only OR SSPL-1.0",
-    "scripts": {
-        "build:antlr4:esql": "antlr -Dlanguage=TypeScript src/antlr/esql_lexer.g4 src/antlr/esql_parser.g4 && node ./scripts/fix_generated_antlr.js && node ./scripts/esql_update_ast_script.js",
-        "prebuild:antlr4": "brew bundle --file=./scripts/antlr4_tools/brewfile",
-        "build:antlr4": "npm run build:antlr4:esql"
-    },
-    "sideEffects": false
-  }
+  "name": "@kbn/esql-ast",
+  "version": "1.0.0",
+  "private": true,
+  "license": "Elastic License 2.0 OR AGPL-3.0-only OR SSPL-1.0",
+  "scripts": {
+    "build:antlr4:esql:parser": "antlr -Dlanguage=TypeScript -lib src/antlr/parser src/antlr/esql_parser.g4",
+    "build:antlr4:esql:lexer": "antlr -Dlanguage=TypeScript -lib src/antlr/lexer src/antlr/esql_lexer.g4",
+    "build:antlr4:esql": "npm run build:antlr4:esql:parser && npm run build:antlr4:esql:lexer",
+    "prebuild:antlr4": "brew bundle --file=./scripts/antlr4_tools/brewfile",
+    "build:antlr4": "npm run build:antlr4:esql"
+  },
+  "sideEffects": false
+}