Add default styles and templates for the bar

[dalyIsaac]

• [ ] Copy a Resources.xaml template to the user's .whim folder when installing
• [ ] Add a commented code snippet in the whim.config.csx to load the template
• [ ] Revisit the design of the default style
• [ ] Package additional default styles to choose from?
• [ ] What should be the height of the bar? Monitor scaling might interfere with this, see https://github.com/dalyIsaac/Whim/pull/723#discussion_r1431029615 and https://github.com/dalyIsaac/Whim/pull/723#discussion_r1429284791