covariance species stats matrix has wrong column headers

[zzeppozz]

Describe the bug

The output matrix is species x species, yet the column headers contain (siteid, x, y) from the input matrix

To Reproduce

Run lmpy.tools.calculate_pam_stats

Expected behavior

All stats should have correct dimensions, content, headers

Additional context

Check all stats matrices by debugging, check sites stats also by converting to raster or geojson and examining in QGIS, check species stats by converting to CSV and examining in a spreadsheet.

[zzeppozz]

Wrangled matrices also have bad headers