Create a service for manipulating settings values

[mkimberlin]

As a System Administrator, I want REST services to manage setting values, so that I can configure the application's behavior through the API.

Acceptance Criteria:

• [x] A new table named "settings" should be created in the database schema.
• [x] The "settings" table should have these columns:
  • [x] name (VARCHAR, PRIMARY KEY, UNIQUE): Name of the setting, corresponding to an option contained in the settings enum.
  • [x] value (TEXT): The current value for the setting.
• [x] A migration script should be created to alter the database schema and add the "settings" table.
• [x] The following services should be implemented:
  • [x] A GET endpoint at /services/settings should retrieve all setting name-value pairs from the database.
  • [x] A PUT endpoint at /services/settings/{name} should allow updating the value for a specific setting.
    • [x] The request body should contain the new value as JSON data.
• [x] Error handling should be implemented to return appropriate status codes for successful and unsuccessful requests.
  • [x] Attempting to store values that do not have an associated value in the settings enum should result in an bad request error.
  • [x] A new permission called CAN_ADMINISTER_SETTINGS should be created and used for protecting both of these new endpoints.

[jackkeller]

@mkimberlin is there an idea of the different settings that we'll want to have control over? Mainly asking to anticipate what we'll be needing on the #2356 side of things.

[mkimberlin]

I think there are a few categories of settings we will likely see out of the gate; one could be theming-related settings potentially (logo, primary/secondary/tertiary colors, etc.), another could be enabling and configuring various integrations (mailjet for example), and there might be some other values from our run.sh script variables that would be better served as admin configurable.

[mjperry91]

@mkimberlin since the PUT endpoint requires us to pass a valid setting object to it, I have left this endpoint as /services/settings instead of adding the name path variable as we can just get that from the object and also verify the ID.

[mjperry91]

PR: https://github.com/objectcomputing/check-ins/pull/2405