Adding a new key-value pair to self action block crashes Editor, making it unresponsive

[kkerti]

Issue:
When commit is used on the self action block and character number is almost 400, Editor crashes.

Reproduction steps:

1. Add a characters to config, so it is almost 400 or try out the Mouse takeover vst controller 1.1 preset's self block on the setup event - that's almost at 400 characters.
2. Add a self action block or fill the action block with new entries
3. On commit, Editor crashes.

[kkerti]

The issue is also true to local action block, probably it will crash on global too.

[SukuWc]

We will fix this along with #914