Prototype the OCM Plugin Manager

[jakobmoellerdev]

The OCM Plugin System currently relies on man assumptions that are problematic for us:

1. The OCM Plugins for upload / download are unable to adjust resources, and instead adjust only accesses, thus they are unable to transform
2. The OCM Plugins have commands for installation and registration, but they can only deal with one byte stream at a time and get forked every time they are called which is quite inefficient.

[Skarlso]

What's Done

• current basic plugin loading and communication via TCP or UDS is working
• interfaces that are hiding the plugin logic has been created
• plugins can be lazy loaded ( meaning they are only started when needed )
• openAPI schema has been created to make plugins able to be generated for other languages
• testing with several hundred concurrent requests and improve stability of the plugin system

What remains

• refactor the code
• deduplication of returned plugins ( right now, a single plugin if it registered for a type could be returned twice )
• use the openapi generated go structs