[MRG] update databases.md with links to UC Davis HPC for distributing large files

[ctb]

This switches our prepared databases links in databases.md over to supplying files via farm.cse.ucdavis.edu for GTDB-RS207 and Genbank, per dib-lab/farm-notes#43.

For review: rendered databases.html from this PR.

Fixes #2179

[codecov]

Codecov Report

Merging #2255 (fef7d3d) into latest (1d1b4e9) will increase coverage by 7.34%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           latest    #2255      +/-   ##
==========================================
+ Coverage   84.85%   92.19%   +7.34%     
==========================================
  Files         131      100      -31     
  Lines       15664    11388    -4276     
  Branches     2249     2249              
==========================================
- Hits        13291    10499    -2792     
+ Misses       2082      598    -1484     
  Partials      291      291              

Flag	Coverage Δ
python	92.19% <ø> (ø)
rust	?

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/core/src/index/revindex.rs
src/core/src/errors.rs
src/core/src/sketch/minhash.rs
src/core/src/ffi/index/revindex.rs
src/core/src/storage.rs
src/core/src/cmd.rs
src/core/src/index/search.rs
src/core/src/ffi/cmd/compute.rs
src/core/tests/storage.rs
src/core/src/ffi/utils.rs
... and 21 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[mr-eyes]

Looks great!