Make path to ktlint-executable configurable instead of using a bundled ktlint-version

[ajans]

Thank you for this great plugin!

The thing that would make my (and maybe your) life easier, would be to set the path to the ktlint-executable used by this plugin (similar to how the Git-executable is configured in Android Studio et al).

As it is now, the plugin-bundled version of ktlint is 0.46.1 according to the changelog on the plugin-homepage.
The latest released official version of ktlint from pinterest is 0.47.1.

Right now I cannot be sure that the latest ktlint-version used by CI and local proxy-installation is reporting / fixing the same issues as the plugin-bundled version.

By using a separate installation of ktlint would enable me to use the same version of ktlint everywhere.

For you as the plugin-author this enhancement would lift the burden of updating the plugin for every new ktlint-version from you.

I understand there may be issues parsing the ktlint-output with an unknown plugin-external ktlint-installation as incompatible changes in the report-format might break the plugin.
If that is the case/concern, then feel free to close this issue as a wontfix (in that case could you please update the plugin to use the latest ktlint-version?).

Thank you for your support!

[nbadal]

Would definitely love to support multiple versions of ktlint - I believe this is essentially a duplicate of #35 though! Let's use that ticket for related discussion