Allow - in database names

[w84thesun]

Description

Closes #1321.

Readiness checklist

• I added tests for new functionality or bugfixes.
• I ran task all, and it passed.
• I added/updated comments for both exported and unexported top-level declarations (functions, types, etc).
• I checked comments rendering with task godocs.
• I ensured that the title is good enough for the changelog.
• (for maintainers only) I set Reviewers (@FerretDB/core), Assignee, Labels, Project and project's Sprint fields.
• I marked all done items in this checklist.

[vercel]

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Name	Status	Preview	Updated
ferret-db	✅ Ready (Inspect)	Visit Preview	Nov 28, 2022 at 5:55PM (UTC)

[codecov]

Codecov Report

Merging #1582 (e50e4fa) into main (278ac31) will decrease coverage by 0.02%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1582      +/-   ##
==========================================
- Coverage   67.60%   67.58%   -0.03%     
==========================================
  Files         284      284              
  Lines       13782    13782              
==========================================
- Hits         9317     9314       -3     
- Misses       3506     3508       +2     
- Partials      959      960       +1     

Impacted Files	Coverage Δ
internal/handlers/pg/pgdb/databases.go	65.00% <ø> (ø)
internal/util/testutil/db.go	87.30% <100.00%> (ø)
internal/util/version/version.go	48.52% <0.00%> (-4.42%)	⬇️
internal/handlers/common/filter.go	84.56% <0.00%> (ø)

Flag	Coverage Δ
integration	63.50% <100.00%> (-0.03%)	⬇️
mongodb	13.92% <100.00%> (-0.03%)	⬇️
pg	52.23% <100.00%> (-0.03%)	⬇️
tigris	36.80% <100.00%> (-0.01%)	⬇️
unit	26.83% <100.00%> (-0.03%)	⬇️

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[rumyantseva]

LGTM! I see you also have a dance tests' draft.