UI: Remove platform string from title bar

[cg2121]

Description

This cleans up the title bar text.

Motivation and Context

Doesn't seem necessary to have in the title bar.

How Has This Been Tested?

Looked at title bar.

Types of changes

• Code cleanup (non-breaking change which makes code smaller or more readable)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the master branch.
• The code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.

[RytoEX]

Personally, I appreciate being able to tell at a glance of the title bar what the user's actual system is. Do we have this string in About somewhere?

[WizardCM]

Realised this removes the platform from more places than we'd like, including the log file, the User Agent in CURL calls (including the updater, maybe?). We might have to have a includePlatform parameter and conditionally include the platform.

[cg2121]

Updated to include parameter about platform.