jetpack_plugin_api_action_links should not be an (esp. autoloaded) option

Very similar to https://github.com/Automattic/jetpack/issues/8268, but this time with `jetpack_plugin_api_action_links`.

On a very small site I manage, `jetpack_plugin_api_action_links` is 5K. Transients are already used to manage the contents of this field, but it's coded as an autoloaded option that is loaded on each and every page request (transferring 5K from the database to the application server each and every time).

Start by comparing this issue with Automattic/jetpack#8268 and tracing the code that creates or updates the `jetpack_plugin_api_action_links` option. Confirm how its transient-backed contents are read and written, then verify that the option is no longer autoloaded while the existing action links continue to work.

Written by the indexing model from the issue text.