Make Moose class TUSK::DB::Version immutable
Add TUSK::DB::Util for sql_file_path and sql_dir

Use new utilities in TUSK::DB::Baseline.
Add upgrade functions for database versioning

Add script db/upgrade.pl and library TUSK::DB::Upgrade.
Add date search schema change to tusk database [TUS-2346]

Added both to upgrade production from baseline to support
content date searching, and also as proof of concept for
db/upgrade.pl database upgrade script.