[UI/UX] Update the look & feel of the GUI (#2884)

* Add @CodingWonders to the About page for his contribution and determination to make WinUtil (and MicroWin) the best software it can be!

* Remove the 'LogoSize' Parameter for About page - Make every sponsor in the sponsors list a link to ChrisTitusTech's Sponsors web link

* Change Theme Option name from 'ConfigTabButtonFontSize' to 'ConfigUpdateButtonFontSize' - Lower its value from 16 to 14

* Change Theme Option name from 'FontSizeHeading' to 'HeadingFontSize' for consistency

* Update 'LinkForegroundColor' for Light Theme to be lighter which'll make link hover color more noticeable

* Update 'Show-CustomDialog' Private Function

- Made a lot of theming/styling choices for Custom Dialogs exposed as parameters.
- Update the documentation for these new parameters in 'Show-CustomDialog' Function.
- Add a Link Hover Effect using 'Add_EVENT' methods (This can be tweaks/tuned-down if needed).
- Made use of 'Title' Parameter for 'Show-CustomDialog' Function inside 'scripts/main.ps1' script, to change Dialog Window Title.
- Now you can change the Logo Size of WinUtil through the 'LogoSize' Theming Option (the option was there, but not used in implementation).

* Preprocessing result

* Fix Settings Popup not closing after losing focus - Add trivial null checks for better debugging of UI code

* Remove unnecessary whitespace indentation in 'main.ps1' script

* Add a new 'Invoke-WPFPopup' Function to Better Handle Showing/Hiding/Toggling of Popups

* Improve 'Invoke-WPFPopup' by @MyDrift-user

Thanks for the improvements :)

---------

Co-authored-by: MyDrift <personal@mdiana.ch>
Co-authored-by: Chris Titus <contact@christitus.com>

functions/public/Invoke-WPFUIElements.ps1

@@ -153,7 +153,7 @@ function Invoke-WPFUIElements {
 
             $label = New-Object Windows.Controls.Label
             $label.Content = $category -replace ".*__", ""
-            $label.FontSize = $theme.FontSizeHeading
+            $label.FontSize = $theme.HeadingFontSize
             $label.FontFamily = $theme.HeaderFontFamily
             $stackPanel.Children.Add($label) | Out-Null