fix: various fixes for the injected formatter

[mehalter]

Some formatters rely on information such as filetype. If that one of those formatters are used by the injected formatter, we need to load the buffer of the injected so that it calculates information such as filetype.

This also validates that _injection_query exists before enabling the injected formatter. Not all treesitter parsers provide this query if they do not have any possible language injections. One example of this is the json parser which doesn't have any injections. This will tell the parser that it doesn't actually need to run for buffers with parsers without injections.