feat: FlinkSQL supports auto complete (#115)

* feat: add antlr4-c3 dependencies

* feat: distinguish table, catalog and database from uid

* feat: move semicolon from sqlStatements to sqlStatement

* chore: move antlr4ts-cli to devDependencies

* feat: improve basic parser and support suggestions of token and syntax

* feat: implement suggest method in sql parsers

* test: flink sql suggestion test cases

* feat: optimize ts defination of suggestion

* feat: add split listener and optimize performance of auto-completion

* test: supplementary flink suggestion unit tests

src/utils/findCaretTokenIndex.ts

@@ -0,0 +1,33 @@
+import { Token } from "antlr4ts";
+import { CaretPosition } from "../../src/parser/common/basic-parser-types";
+
+/**
+ * find token index via caret position (cursor position)
+ * @param caretPosition 
+ * @param allTokens all the tokens
+ * @returns caretTokenIndex
+ */
+export function findCaretTokenIndex(caretPosition: CaretPosition, allTokens: Token[]) {
+    const { lineNumber: caretLine, column: caretCol } = caretPosition;
+    let left = 0;
+    let right = allTokens.length - 1;
+
+    while(left <= right) {
+        const mid = left + ((right - left) >> 1);
+        const token = allTokens[mid];
+        if (token.line > caretLine || (
+            token.line === caretLine
+            && token.charPositionInLine + 1 >= caretCol
+        )) {
+            right = mid - 1;
+        } else if (token.line < caretLine || (
+            token.line === caretLine
+            && token.charPositionInLine + token.text.length + 1 < caretCol
+        )) {
+            left = mid + 1;
+        } else {
+            return allTokens[mid].tokenIndex
+        }
+    }
+    return null;
+}