Loki: Implement decolorize logql operation (#68972)

* Loki: Implement decolorize operation

* Fix tests

public/app/plugins/datasource/loki/querybuilder/parsing.ts

@@ -7,6 +7,7 @@ import {
   Bool,
   By,
   ConvOp,
+  Decolorize,
   Filter,
   FilterOp,
   Grouping,
@@ -176,6 +177,11 @@ export function handleExpression(expr: string, node: SyntaxNode, context: Contex
       break;
     }
 
+    case Decolorize: {
+      visQuery.operations.push(getDecolorize());
+      break;
+    }
+
     case RangeAggregationExpr: {
       visQuery.operations.push(handleRangeAggregation(expr, node, context));
       break;
@@ -368,6 +374,15 @@ function getLabelFormat(expr: string, node: SyntaxNode): QueryBuilderOperation {
   };
 }
 
+function getDecolorize(): QueryBuilderOperation {
+  const id = LokiOperationId.Decolorize;
+
+  return {
+    id,
+    params: [],
+  };
+}
+
 function handleUnwrapExpr(
   expr: string,
   node: SyntaxNode,