[ES|QL] accept negated index patterns (#184528)

## Summary

`*, -.*` is now acceptable.


### Checklist
- [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

Co-authored-by: Stratoula Kalafateli <efstratia.kalafateli@elastic.co>

packages/kbn-esql-validation-autocomplete/src/shared/helpers.ts

@@ -521,7 +521,7 @@ export function columnExists(
 }
 
 export function sourceExists(index: string, sources: Set<string>) {
-  if (sources.has(index)) {
+  if (sources.has(index) || index.startsWith('-')) {
     return true;
   }
   return Boolean(fuzzySearch(index, sources.keys()));

packages/kbn-esql-validation-autocomplete/src/validation/esql_validation_meta_tests.json

@@ -430,6 +430,11 @@
       "error": [],
       "warning": []
     },
+    {
+      "query": "from *,-.*",
+      "error": [],
+      "warning": []
+    },
     {
       "query": "from indexes*",
       "error": [

packages/kbn-esql-validation-autocomplete/src/validation/validation.test.ts

@@ -352,6 +352,7 @@ describe('validation logic', () => {
       testErrorsAndWarnings(`from *ex*`, []);
       testErrorsAndWarnings(`from in*ex`, []);
       testErrorsAndWarnings(`from ind*ex`, []);
+      testErrorsAndWarnings(`from *,-.*`, []);
       testErrorsAndWarnings(`from indexes*`, ['Unknown index [indexes*]']);
 
       testErrorsAndWarnings(`from remote-*:indexes*`, []);