Rename service.Application to service.Server

[rakyll]

The collector service server is currently named Application. In Otel, "application" has a significance to refer to the user applications to instrument. We might rename it to Server which would be more representative.

[rakyll]

Or why don't we call it Collector?

[eddyleelin]

Sorry for the newbie question, but would this be a breaking fix? Would the changes be simply renaming the service.Application file and its variables, as well as everywhere that calls it, or are there any outside dependencies?

[bogdandrutu]

@eddyleelin it is, but we are allowed to do that in order to cleanup the code in this phase of the project.

[eddyleelin]

Great! Thanks for the response. I could try to take this one on then! @bogdandrutu