Move sub-classes of "NotifyIcon", "ToolStripDropDownItem", "ToolStripSplitButton" and "ToolStripStatusLabel" classes to their own files

[SergeySmirnov-Akvelon]

Proposed changes

• Moved sub-classes of "NotifyIcon", "ToolStripDropDownItem", "ToolStripSplitButton" and "ToolStripStatusLabel" classes to their own files

Customer Impact

• No

Regression?

• No

Risk

• Minimal

Test environment(s)

• Microsoft Windows [Version 10.0.19041.388]
• .NET Core SDK 6.0.0-alpha.1.21073.5

Microsoft Reviewers: Open in CodeFlow

[codecov]

Codecov Report

Merging #4612 (7090dc9) into main (f195452) will increase coverage by 0.00759%.
The diff coverage is n/a.

@@                 Coverage Diff                 @@
##                main       #4612         +/-   ##
===================================================
+ Coverage   97.96079%   97.96838%   +0.00758%     
===================================================
  Files            542         542                 
  Lines         263533      263533                 
  Branches        4937        4937                 
===================================================
+ Hits          258159      258179         +20     
+ Misses          4494        4478         -16     
+ Partials         880         876          -4     

Flag	Coverage Δ
Debug	97.96838% <ø> (+0.00758%)	⬆️
production	100.00000% <ø> (?)
test	97.96838% <ø> (+0.00758%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.