Fix MilCodeGen and Csp build

[ThomasGoulet73]

Description

This PR aims to fix MilCodeGen which seems to be very outdated and it doesn't seem like it ever worked in this repo (It probably worked in the internal repo for Microsoft).

The goal of this PR is to fix MilCodeGen and Csp to be able to build and run MilCodeGen. I'll open other PRs to fix the templates to match the generated code and then other PRs which includes the modification to the generated code.

I cherry-picked the changes from #6135, reworked it to make it easier to use and updated the documentation.

Customer Impact

None, this is non-shipping code.

Regression

No.

Testing

Local build + I generated the code locally using #6135 rebased over this PR.

Risk

Low to none, this is non-shipping code and MilCodeGen already doesn't run so it can't get any worse.

Microsoft Reviewers: Open in CodeFlow

[dipeshmsft]

@ThomasGoulet73 I have reviewed the PR and left the comments. I am still to look into GenerateFiles.cmd, Resources.xml, Resources.xsd and related files, but I will be done by tomorrow.

[ThomasGoulet73]

Thanks @dipeshmsft, I believe I've applied all your change requests and answered your questions. I also pulled main to fix the conflicts.

Let me know if there's anything else.

[dipeshmsft]

Thanks @ThomasGoulet73 for the quick turnaround on the comments and feedback. I have reviewed the PR again, and I have only one concern that I have left in the comments. Apart from that this PR is good to go.

[ThomasGoulet73]

Thanks @ThomasGoulet73 for the quick turnaround on the comments and feedback. I have reviewed the PR again, and I have only one concern that I have left in the comments. Apart from that this PR is good to go.

Great, I pushed a commit and answered your comment.

[dipeshmsft]

Thanks @ThomasGoulet73 for support on this PR. I will wait for subsequent PRs on MilCodeGen.

[ThomasGoulet73]

Thanks @dipeshmsft.

P.S.: I opened #10429 to track the rest of the work.