[Scylla] - Expose certain settings over the webserver for Argos setting

[jr1221]

Description

Some settings should be admin/user facing on Argos. Provide a HTTP post endpoint for each of them with param.

Acceptance Criteria

• Can toggle SCYLLA_DATA_UPLOAD_DISABLE
• Can set SCYLLA_SOCKET_DISCARD_PERCENT
• Can set SCYLLA_BATCH_UPSERT_TIME
• Can toggle SCYLLA_SATURATE_BATCH

Proposed Solution

Use Atomic* types declared above main() in order to provide the functionality.

Have a POST endpoint for each setting (argos/<setting>/set) using a query or param (idk best) with the relevant Atomic passed in as a extension with a static lifetime. The controller will call load with relaxed ordering.

Change the functions that use these settings to take in an atomic type, and check the Atomic* type at each action. Ensure performance regressions are not major with the Atomic* types by using relaxed ordering on store and load.

Mocks

No response

[jr1221]

Also add get for each param so the client can query the status.