[Feature] Generic key / value store for plugin config

[Tweeticoats]

Is your feature request related to a problem? Please describe.
For plugin config it would be useful to have a generic key / value store configuration needed for plugins.
If there was a graphql api for get_config(key) and update_config(key,value)

Ideally you could store a json object as the value allowing you to store as many options as needed for the scraper or plugin.

Describe the solution you'd like
A table in the database to store this config:
config (key varchar(255) primary key, value text)

A put config method in graphql:
mutation update_config(key,value)

A get config method:
query get_config(key)

Describe alternatives you've considered
Storing this config in a studio.
You can easily create a new studio if it does not exist and store all the config in the description field as that is a text field.

[Maista6969]

Solved by #4143