Appsettings.json - support for custom tags

Hi :)

PSU sets a set of default tags on the computer object, that is based on the environment its in.
It would be ideal that we could add custom tags, such as the environment (Prod / Test / Dev), Owner, business service, etc - to align it better with our current CMDB platform.

I believe it should be in the appsettings.json, since this one is not normally synced to Git - so setups with a prod and a test instance of PSU, will not conflict on this.
It should also allow us to write anything we want, so that we arent "stuck" with a key/value set, defined from Devolutions.


Bonus - if the tags could be read on the fly, that would be nice. So adding a new tag, wouldnt have to restart the service, for it to appear - but its a nice to have thing.