Enable reading of additional .series files
Added support for reading in addition .series files.
Supported extensions added in this commit are:
vtm.series vtmb.series vthb.series vth.series vtp.series vtt.series vtu.series vtk.series vts.series vtr.series pvtp.series pvtu.series pvtt.series pvti.series pvts.series pvtr.series pvtk.series ply.series stl.series
A test for the vtp.series extension is included.
Closes #18251 (closed).