micropub.rocks should ignore whitespace differences for the 6XX tests

[bear]

In order to get my service to pass test 602 I had to strip the newline from the end of the content, for example this failed: "content": ["Test of querying the endpoint for the source content\n"]

but this now means that i've changed how my posted content is stored and retrieved solely to pass a testing tool for something that shouldn't even be looked at by the test tool.

An contrived example (but valid IMO) would be me posting a CREATE for

"This is\na contrived example"

via my micropub which my code would then create my markdown as

This is
a contrived example

which would then be returned as

["This is", "a contrived example"]