[BUGFIX] improve handling of TYPO3 version

getNumericTypo3Version() needs to be more flexible when converting
the defined version number into one that can be used by the EM.

Resolves: #23902
Releases: 6.2
Change-Id: Ie2ed54c1383e3c6ff9631608e2e9e471ef109952
Reviewed-on: https://review.typo3.org/27509
Reviewed-by: Markus Klein
Tested-by: Markus Klein