fix(filter): correctly replace project title in filter query

Resolves https://community.vikunja.io/t/filter-option-to-exclude-a-tag-project-etc/1523/6

frontend/src/helpers/filters.ts

@@ -33,6 +33,7 @@ export const AVAILABLE_FILTER_FIELDS = [
 	...DATE_FIELDS,
 	...ASSIGNEE_FIELDS,
 	...LABEL_FIELDS,
+	...PROJECT_FIELDS,
 ]
 
 export const FILTER_OPERATORS = [