Installer support to opt into index creation

[danielmarbach]

This pull request is based on the work of @hasancanguler started in #769 and applies a few changes on top of it.

• Database and collection access consistently uses the database and collection settings. The settings were introduced as part of Ensure read and write concerns are set properly #17. If no explicit settings are passed the default settings from the client settings are applied which are either default too or overridden when the corresponding constructor of the client is called. It wasn't entirely clear from the code changes why the setting wasn't consistently overridden in all cases. The only reason I could come up with is that the settings we currently use might be a bit slower because in a cluster the client has to wait for more nodes to acknowledge which could influence the startup behavior when many sagas are present. On the other hand, other collection accesses have deliberately opted in for non-default read and write concerns, which begs the question of whether this was simply overlooked.
• By moving relevant things into the installer it is possible to start leveraging the async APIs on the client
• Introduce an API to disable the installers of the persistence even when the installers are enabled (other persistences offer that too)
• Introduce similar concepts for the subscription part to align the code base.

[danielmarbach]

This is shaping up. A few things that we probably need to discuss

• There is some redundancy between things used in feature setup and things used in the installer. I, personally, don't think it is a big deal and would leave it as is for now.
• As a first start there is a single "Disable" method similar to how other persisters have this global switch. Technically we could also support more granular switches, but I would postpone this to future iterations if necessary.
• Previously the outbox code did always discover the gap between the index expiry drifting and recreated it. Now with the installer that would not happen anymore when installers disabled (which is expected). Should we add a check for drifts and log warn and add the possibility to disable the check?