[Fleet] Add ability to configure local queues

[mostlyjason]

Describe the feature:
In Beats today, users have the ability to specify settings for the local queue, either in memory on disk. We'd like to expose these options in the Fleet UI so users can set them. These are advanced settings so they don't need to be prominent, but it'd be nice if there was a way for users to set it. These settings apply to FB/MB not to an integration, so perhaps it makes sense to specify them on the agent policy?

Describe a specific use case for the feature:

• As a service owner, I'd like the ability to specify settings for my local queues to add more memory or persist to disk

[elasticmachine]

Pinging @elastic/ingest-management (Team:Ingest Management)

[zez3]

Can we also have the path also, we will store this disk queue on a raid1 disk for more redundancy.
https://www.elastic.co/guide/en/beats/filebeat/current/configuring-internal-queue.html#configuration-internal-queue-disk-reference

I subscribe to have this in the agent policy.

[zez3]

Max size is anyway required
https://www.elastic.co/guide/en/beats/filebeat/current/configuring-internal-queue.html#_max_size_required

[zez3]

@jamiehynds
Any updates on this? Can this be taken on the roadmap?