Validate XLSX file created by annex_write_stats()
.
Checks if all required sheets/columns are available and that
all user-modified META information has been entered correctly.
Value
Some checks will cause an error and stop execution.
Others will cause a message with some information on what
has to be fixed to make the document valid. If the function
does not stop due to an error it will return TRUE
if the file has been validated as proper, or FALSE
if issues have been found.