Viewer should respect "Hide pointer while typing" Windows setting

Currently, the viewer always hides the cursor while typing. However, this might not be desirable for every user. As for Windows operating systems, they come with a setting controlling this behavior (see attached screenshot). Unfortunately - like many other Windows applications as well - this setting isn't applied automatically to any application and the application has to implement this behavior explicitly, with the viewer not doing so.

Proposed change is to respect the user setting made in the operating system and only hide the cursor while typing if the user has enabled this behavior.

Test plan:

• Check "Hide cursor while typing" option in the "Mouse" system settings
• Start the viewer and type in any textbox
• Cursor should be hidden while typing
• Uncheck "Hide cursor while typing" option in the "Mouse" system settings while still being logged in
• Type in any textbox and notice cursor is still visible
• Restart the viewer and type in any textbox
• Notice cursor is visible while typing

Commit for proposed change: https://bitbucket.org/Ansariel/storm-2151/commits/df540da7ead66c389168bde408597ef195b9cecf