feat: add more recursion endpoints

[janniks]

Adding these endpoints covered by ord https://docs.ordinals.com/inscriptions.html?highlight=rec#recursion

A couple other endpoints that inscriptions may access are the following:

/blockheight: latest block height.
/blockhash: latest block hash.
/blockhash/<HEIGHT>: block hash at given block height.
/blocktime: UNIX time stamp of latest block.

---

todo

• [x] ~cacheing: what's your preferred etag/cacheing option? we could add a stats/inscriptioncountperblock cache for most, and a custom new cache for the /:blockheight show endpoint.~

[github-actions[bot]]

Vercel deployment URL: https://ordinals-5ut3rkhrx-blockstack.vercel.app :rocket:

[codecov[bot]]

Codecov Report

Merging #144 (a3c3add) into develop (a7674a9) will decrease coverage by 4.25%. The diff coverage is 100.00%.

:exclamation: Current head a3c3add differs from pull request most recent head 389ec23. Consider uploading reports for the commit 389ec23 to get more accurate results

@@             Coverage Diff             @@
##           develop     #144      +/-   ##
===========================================
- Coverage    91.98%   87.74%   -4.25%     
===========================================
  Files           26       34       +8     
  Lines         2970     3622     +652     
  Branches       239      294      +55     
===========================================
+ Hits          2732     3178     +446     
- Misses         236      440     +204     
- Partials         2        4       +2     

Impacted Files	Coverage Δ
src/api/init.ts	70.49% <100.00%> (+1.52%)	:arrow_up:
src/api/routes/recursion.ts	100.00% <100.00%> (ø)
src/api/schemas.ts	100.00% <100.00%> (ø)
src/pg/pg-store.ts	99.27% <100.00%> (+1.79%)	:arrow_up:

... and 19 files with indirect coverage changes

[janniks]

Forgot about this one. A lot of recursive viewing doesn't really work in our explorer due to security concerns, so it might not be too important to have these endpoints right now..