server(plugins): upate without downtime

[kontrollanten]

Description

• Create a new folder each time a new plugin/theme is installed or updated. The folder name is created based on the package.json content hash.
• Removes the need to decache nodes require cache when updating plugins.
• Run install/update/uninstall operations in jobs.

Related issues

closes #4828

Has this been tested?

• [ ] 👍 yes, I added tests to the test suite
• [ ] 💭 no, because this PR is a draft and still needs work
• [ ] 🙅 no, because this PR does not update server code
• [ ] 🙋 no, because I need help