Improve las_check() CRS checking

[ppoyk]

Function las_check() reports "Inconsistent CRS across files" when checking a LAScatalog object with multiple LAS file formats.

In my case, after separately checking each file included in the catalog, all files did have identical CRS information.
This contradicts with the output of las_check().

I suspect this has to do with only some files in the catalog having a WKT defined. LAS files with < 1.4 specification lack WKT information.
(Checking WKTs is supposedly included in the "CRS check" section of las_check().)

Possible solution would be to only check file CRSs, output the check results, and warn the user if also WKTs are present.
Another solution would be to convert WKTs / CRSs to each other. Then check that all files concur. Warning should also be raised if any file has both CRS and WKT defined, but they do not equal after conversions.

[Jean-Romain]

In my opinion this is the expected behavior. las_check is giving you a warning that there is something to check. You checked it. It is ok. End of the story. Don't you agree?

[ppoyk]

You are correct that the general check results should guide the user to make more detailed investigations.
However, I think the function could handle the CRS check even better by converting the WKT and CRS values such that they are comparable.
This is only a minor issue.

[Jean-Romain]

My concern with that suggestion is that it gonna be very tedious for a small gain. CRS interpretation is prone to minor variation. For example in your case are you sure that the EPSG code returns the exact same CRS as the WKT string?