feat: ignore case for shell error messages and allow popup min/max width customization

[yermulnik]

Ignore case when comparing shell error messages from git CLI.

> git --version
git version 2.47.1

> git status
fatal: not a git repository (or any of the parent directories): .git

The "not" word is all lowercase.

While here also allow to customize popup min and max width

[yermulnik]

@mralusw ?

[yermulnik]

Bump