Kibana version: master

Describe the bug: Inputs for axis title overwrites are not debounced and due to that are pretty laggy.

Steps to reproduce:

1. Go to Lens
2. Configure custom chart title
3. Typing is very slow

Expected behavior:
Should be fast, once the user stops typing, the chart should update once

Screenshots (if relevant):

Errors in browser console (if relevant):

Provide logs and/or server output (if relevant):

Any additional context:
We do this for column label already - this logic should be generalized and used here as well