include `git_head` detail in all human-focused version strings

[TallTed]

@pkleef @openlink @imitko @smalinin @kidehen @HughWilliams @mitache @IvanMikhailov

Can we please start to include git_head info here (line 2740 of sql/facet_view.sql) and anywhere else st_dbms_ver is displayed/output?

st_build_date doesn't provide any insight into the instance version, only the date of its compilation -- which has no relation to when the st_dbms_ver was set nor when the code being compiled was obtained from the repo. st_dbms_ver is also disconnected from the human/marketing "version", e.g., VOS 7.2.6.1 does not correspond to an st_dbms_ver of 07.20.06.01 nor 07.02.06.01.

Originally posted by @TallTed in #21 (comment)