Plastic SCM plugin 1.5.1 release for Unreal Engine 4.27 and 5.0, with support for upcoming UE5.1

[SRombauts]

Hi,

I have good news from Epic Games: they have merged the latest version of our Plastic SCM plugin v1.5.1 on ue5-main for the upcoming Unreal Engine 5.1! 
https://github.com/PlasticSCM/UE4PlasticPlugin/releases/tag/1.5.1 was only a bugfix release on top of already merged 1.5.1, including support for some recent breaking code changes.
I have now checkout the latest commit , rebuilt the editor, and run our validation steps in order to be on the safe side

Enjoy!
Sébastien

What's Changed:

• Rename back the provider to "Plastic SCM" so it's the same as in Engine and users can easily switch from one to the other
• Fix connection at init for commandlets by @SRombautsU in #29
• Optimize the Revert command to operate on all the files at once for Unreal 5 by @SRombautsU in #27
• Fix performance issue with the new call to "history" added to each UpdateStatus() by @SRombautsU in #30