Combine all paste linters

[AshesITR]

let's think about it in an issue. there are a few paste-related linters incoming. as I was writing this PR I thought it might make sense to merge them all into just one paste_linter.

another thing I see sometimes that I'd like to lint is paste0(x, collapse=). if there's only one input it's the same as the paste version, but it'd be nice to be consistent and the paste0 looks a bit distracting/misleading to me

Originally posted by @MichaelChirico in #997 (comment)

[MichaelChirico]

Our existing linters relating to paste / paste0 are:

• PasteSepLinter: paste(sep = "") ➡️ paste0()
• PasteToStringLinter: paste(collapse = ", ") ➡️ toString()
• Upstreaming linters from Google's internal linting suite #884 PasteFilePathLinter: paste(sep = "/") ➡️ file.path()
• Upstreaming linters from Google's internal linting suite #884 PasteStrrepLinter: paste(rep(), collapse="") ➡️ strrep()

In addition there were two new "unusual" usages to consider:

• paste0(sep = "<anything>") ➡️ paste(sep = "<anything>")
• paste0(x, collapse = ) ➡️ paste(x, collapse = )

[AshesITR]

The toString() lint could also point to glue::glue_collapse() in its message in case the actual intention is to create a human friendly enumeration.

[MichaelChirico]

Closing here; tracking the rest in #1108 after release