Fix `imeFastEdit` option being reset after `updateSettings` call

[budnix]

Context

The PR fixes a bug where the IME editor mode was deactivated after the regular updateSettings method call. The internal state of the FocusManager was cleared unintentionally.

How has this been tested?

I tested the changes locally and I covered the fix with a new test.

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)

Related issue(s):

1. fixes https://github.com/handsontable/dev-handsontable/issues/1865

Affected project(s):

• [x] handsontable

Checklist:

• [x] I have reviewed the guidelines about Contributing to Handsontable and I confirm that my code follows the code style of this project.
• [x] I have signed the Contributor License Agreement

[github-actions[bot]]

Launch the local version of documentation by running:

npm run docs:review a83062aea811e104cd46d3b29f4349fa1b5e130d