Refactoring: Move NSIS files to libs\

[ann0see]

Short description of changes

Moves the NSIS files to the libs\ folder similar to ASIO-SDK. This is done to clean up the repo and simplify the structure. #2601 was the initial draft, and I plan multiple smaller PRs which are more testable.

CHANGELOG: Refactoring: Moved around files to clean up the repository
Context: Fixes an issue?

Related to: #2601

Does this change need documentation? What needs to be documented and how?

No.

Status of this Pull Request

Ready for testing and review.

What is missing until this pull request can be merged?
Testing. I'm a bit worried since the other PR I mentioned didn't fail, but there were some suspected issues.

Checklist

• I've verified that this Pull Request follows the general code principles
• I tested my code and it does what I want
• My code follows the style guide
• I waited some time after this Pull Request was opened and all GitHub checks completed without errors.
• I've filled all the content above

[ann0see]

I just read the following:

Building the projects in this solution one at a time. To enable parallel build, please add the "-m" switch.

Probably it's worth adding -m on the nsProcess build.

[ann0see]

Ok. I successfully installed JACK and ASIO build on my Win 11 machine.

[hoffie]

Does this need updating as well?

.github/workflows/autobuild.yml-314-          path: |
.github/workflows/autobuild.yml-315-            C:\Qt
.github/workflows/autobuild.yml-316-            C:\ChocoCache
.github/workflows/autobuild.yml:317:            ${{ github.workspace }}\windows\NSIS
.github/workflows/autobuild.yml-318-            ${{ github.workspace }}\libs\ASIOSDK2

We want to cache the downloaded NSIS source, but not (even if we seem to...?) anything coming from our repo or any build artifacts.

[ann0see]

.github/workflows/autobuild.yml:317: ${{ github.workspace }}\windows\NSIS

needs updating. I don't think the other ones have changed?

[hoffie]

I don't think the other ones have changed?

Sorry, I just added the other lines for context. NSIS is what I meant.

[hoffie]

Looks good to me.

I've triggered two further CI runs and observed that NSIS source caching works properly:
https://github.com/jamulussoftware/jamulus/runs/8141543452?check_suite_focus=true#step:10:48

Using D:\a\jamulus\jamulus\windows..\libs\NSIS\NSIS-source from previous run (e.g. actions/cache)