Report every unique range in message parts

[TexKiller]

Should resolve #39

[mroch]

thanks for this PR! however, we've removed the non-LSP integration that this was affecting.

also, I think that in the years since #39, Flow has greatly improved our error positioning such that it should always report the error at the call site, not at the definition, so we only want to show the error at the "primary" location, not at each of the reference locations. as far as I can tell, this is working as expected: