Event Definition Edit: Query parameter still flagged "Undeclared / unbound" after being declared

## Expected Behavior
Once a query parameter is declared and bound to a lookup table (with a default value), the event definition's **Filter** step should validate and the "undeclared / unbound parameter" error should clear.

## Current Behavior
The Filter step appears to keep showing `Undeclared parameter: Unbound required parameter used: ` even after the parameter has been declared and bound to a lookup table with a default value.

See here for a Filter & Aggregation event definition after a lookup table parameter has been defined.

## Possible Solution
Not sure yet, but could be stale client-side validation state, or the binding not actually persisting. Possibly related to the older (closed) #12261 "Undeclared parameter error persists".

## Steps to Reproduce (for bugs)
1. Create a lookup table named `action`.
1. Edit an event definition and set the Filter Search Query to `action:$action$ AND http_response_code:200`.
1. Click the `action` parameter chip and declare it from a lookup table (Lookup Table Key `action`, Default Value `login`); save the declaration.
1. Observe that the Filter step still shows `Undeclared parameter: Unbound required parameter used: act`.
1. Save the event definition and see that the event definition saves successfully with the parameter.

## Context
Hit this while setting up a parameterized event definition — the false error blocks validating/saving the definition even though the parameter is fully declared.

## Your Environment
* Graylog Version: 7.2.0-SNAPSHOT

## Checklist
[] This issue fix need to be backported.
[] Does this issue have **security** implications? No