[ES|QL] Make getActions more resilient to lack of callbacks (elasti…

…c#180260)

## Summary

Now `getActions` provides some more fixes in case of lack of callabacks,
like with unquoted fields.
The feature is still experimental and applies only to unquoted fields
(disabling the existence check on quoted fields).

### Checklist

- [x]
[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials
- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

packages/kbn-esql-ast/src/antlr_error_listener.ts

@@ -25,8 +25,8 @@ export class ESQLErrorListener extends ErrorListener<any> {
     const textMessage = `SyntaxError: ${message}`;
 
     const tokenPosition = getPosition(offendingSymbol);
-    const startColumn = tokenPosition?.min + 1 || column;
-    const endColumn = tokenPosition?.max + 1 || column + 1;
+    const startColumn = offendingSymbol && tokenPosition ? tokenPosition.min + 1 : column + 1;
+    const endColumn = offendingSymbol && tokenPosition ? tokenPosition.max + 1 : column + 2;
 
     this.errors.push({
       startLineNumber: line,

packages/kbn-esql-validation-autocomplete/README.md

@@ -116,6 +116,7 @@ const {title, edits} = await getActions(
   queryString,
   errors,
   getAstAndSyntaxErrors,
+  undefined,
   myCallbacks
 );
 
@@ -124,6 +125,33 @@ const {title, edits} = await getActions(
 console.log({ title, edits });
 ```
 
+Like with validation also `getActions` can 'relax' its internal checks when no callbacks, either all or specific ones, are passed.
+
+```js
+import { getAstAndSyntaxErrors } from '@kbn/esql-ast';
+import { validateQuery, getActions } from '@kbn/esql-validation-autocomplete';
+
+const queryString = "from index2 | keep unquoted-field"
+
+const myCallbacks = {
+  getSources: async () => [{name: 'index', hidden: false}],
+  ...
+};
+const { errors, warnings } = await validateQuery(queryString, getAstAndSyntaxErrors, undefined, myCallbacks);
+
+const {title, edits} = await getActions(
+  queryString,
+  errors,
+  getAstAndSyntaxErrors,
+  { relaxOnMissingCallbacks: true },
+  myCallbacks
+);
+
+console.log(edits[0].text); // => `unquoted-field`
+```
+
+**Note**: this behaviour is still experimental, and applied for few error types, like the unquoted fields case.
+
 ### getAstContext
 
 This is an important function in order to build more features on top of the existing one.