chore: make max message size configurable only for clusterIds different than 1

[gabrielmer]

Background

In cluster-ids different than 1 (aka not the Waku Network), we want the max size of a WakuMessage to be configurable.
For cluster id one, it should comply with the hard limit of the Waku Network.

We should also update the checks at the REST API handler to use the configurable value and not the default limit.

Acceptance criteria

• max message size should be configurable outside of cluster-id 1
• message validation checks should use the configurable value instead of the hardcoded default

[gabrielmer]

This is the proc that has to be modified at the REST level:

It also doesn't have to be async