fix: checkcomp filter formatting updates from Samu Sillanpaa. This is a custom filter for helium scanlog's missing files-per-component reporting.

fix: filterwhatcomp and filtercheckcomp - correctly strip absolute directory and replace with EPOCROOT on windows.

fix: failure of make engine test when a make engine alias contains a modifier. There can be more than one variant per alias via "." e.g. make.extrastuff where make and extrastuff are variants.

Fix up file testing with checkwhatcomp and make epocroot driveletter stripping case insensitive.

FilterCheckComp - checking file existence by component

Merge