lm_to_projdata output filename prefix with "." leads to suffix issue

Playing with lm_to_projdata.par output filename prefix and the usage of output filename prefix := Unlisted/Delayed/Sim_test.Delayed results in filename header Sim_test.hs and binary Sim_test.Delayed_f1g1d0b0. Sim_test.hs does link correctly with name of data file := Sim_test.Delayed_f1g1d0b0.

Tracking this down it leads to
https://github.com/UCL/STIR/blob/aae4c92e9cb63699997573b4e02b78fdb86d373d/src/listmode_buildblock/LmToProjData.cxx#L827
which is defined
https://github.com/UCL/STIR/blob/aae4c92e9cb63699997573b4e02b78fdb86d373d/src/IO/interfile.cxx#L1439-L1474

In the lm_to_projdata.parfile, using output filename prefix := Unlisted/Delayed/Sim_test.Delayed.hs (adding the .hs which the above method can handle) results in file outputs of Sim_test.Delayed.hs (expected header) and Sim_test.Delayed.hs_f1g1d0b0 (wierd). This is becasue of
https://github.com/UCL/STIR/blob/aae4c92e9cb63699997573b4e02b78fdb86d373d/src/listmode_buildblock/LmToProjData.cxx#L565-L567
which is called before the filename is passed to write_basic_interfile_PDFS_header.

This is more of an annoyance than anything else. Functionally everything is okay, naming convention is just not consistant.

Start with the referenced filename handling in src/listmode_buildblock/LmToProjData.cxx around lines 565-567 and 827, then inspect the cited write_basic_interfile_PDFS_header implementation in src/IO/interfile.cxx. Reproduce both parameter-file cases and make the header and binary filenames follow one consistent prefix convention without breaking the existing link between them.