add link script for powershell

[getchoo]

Related Issue

n/a

Implementation

this a powershell implementation of link.sh. it allows for an easier development workflow by automatically copying and linking required files from retail TF2 and game_clean, while only needing one parameter (-TF2Dir).

Screenshots

Checklist

• [x] No other PRs implement this idea.
• [x] This PR does not introduce any regressions.
• [x] I certify that this PR is my own entirely original work, or I have permission from and have attributed the relevant authors.
• [x] I have agreed to and signed this project's Contributor License Agreement.
• [ ] This PR only contains changes to the engine and/or core game framework
• [x] This PR targets the changes branch.

• [ ] This change has been filed as an issue.
• [x] No other PRs address this.
• [x] This PR is as minimal as possible.
• [x] This PR does not introduce any regressions.
• [x] This PR has been built and locally tested on at least one platform.
• [ ] This PR has been tested on all platforms, on both a dedicated server and on a listen server.

Testing Checklist

	Client	Server	Version
Windows	tested	tested	windows 11
Linux	n/a	n/a	n/a
Mac OS	n/a	n/a	n/a

Caveats

running tc2 after compiling is easier now /s this requires administrator privileges due to limitations of windows

Alternatives

using git bash with link.sh :trollface:

[getchoo]

rebased onto the new commits from changes and implemented some of the changes suggested in #629

the game_clean and output directories are also nice constants now :)