Remove references to coordinator endpoints from the LRAClent API

[mmusgrov]

The ClientAPI java doc and Java constants imply that there must be an LRA coordinator endpoint somewhere in the system (for example LRA_COORDINATOR_HOST_KEY and LRA_COORDINATOR_PORT_KEY). The implementation of this specification should be flexible enough to not require coordinators to be listening on network endpoints. Such references should be removed from LRAClient.

[xstefank]

I will create a PR for this issue

[mmusgrov]

@xstefank don't we need a resolution to #62 before removing this?

[xstefank]

issue #62 will cover conversion to MP config definition of the properties, i.e. how the properties can be defined. In this one I will just update the property names.

[mmusgrov]

@xstefank When you have the smallrye implementation ready I think we can merge this PR