Introduce auxiliary scripts

[oschwengers]

Often, the usage of Bakta is a necessary upfront task followed by deeper analyses implemented in custom scripts.

Therefore, we introduce a new directory scripts where we'd like to collect & offer a pool of scripts addressing common tasks.

As a starter:

• collect-annotation-stats.py: Collect annotation stats for a cohort of genomes and print a condensed TSV.
• extract-region.py: Extract genome features within a given genomic range and export them as GFF3, Embl, Genbank, FAA and FFN

Of course, pull requests are welcome ;-)

[oschwengers]

This is a merger of a region extraction script I wrote some time ago and #246 - thanks @AhmedElsherbini ;-)