feat: make AccessKey the key entrypoint for public apis

[appcypher]

This PR brings the multiple ways of generating key materials for accessing nodes in a filesystem under a single type. The AccessKey now becomes the only way of accessing the nodes in a file system. It is important to note that the Snapshot aspect of AccessKey is not at all functional right now.

This PR implements the following features

• AccessKey implementation
• Wasm binding for AccessKey

Test plan (required)

• Testing

  scripts/rs-wnfs test

Closing issues

Fixes #249

[codecov]

Codecov Report

Merging #285 (8e976db) into main (085242d) will increase coverage by 0.99%.
The diff coverage is 51.23%.

@@            Coverage Diff             @@
##             main     #285      +/-   ##
==========================================
+ Coverage   60.47%   61.47%   +0.99%     
==========================================
  Files          40       40              
  Lines        2763     2707      -56     
  Branches      690      679      -11     
==========================================
- Hits         1671     1664       -7     
+ Misses        622      571      -51     
- Partials      470      472       +2     

Impacted Files	Coverage Δ
wnfs/examples/private.rs	0.00% <0.00%> (ø)
wnfs/examples/tiered_blockstores.rs	0.00% <0.00%> (ø)
wnfs/src/root_tree.rs	67.69% <ø> (ø)
wnfs/src/private/link.rs	49.33% <22.22%> (+0.68%)	⬆️
wnfs/src/private/forest.rs	64.10% <50.00%> (-4.08%)	⬇️
wnfs/src/private/share.rs	72.09% <50.00%> (+8.12%)	⬆️
wnfs/src/private/keys/access.rs	53.33% <53.33%> (ø)
wnfs/src/private/node/node.rs	65.78% <65.51%> (-0.88%)	⬇️
wnfs/src/private/keys/privateref.rs	55.26% <66.66%> (ø)
wnfs/src/private/directory.rs	69.59% <80.00%> (+1.74%)	⬆️
... and 3 more

... and 2 files with indirect coverage changes

[matheus23]

Same with this PR, I'd prefer this to be marked as "feat" instead of "fix".
(Also I don't think the "(api)" means anything to release-please. IIUC, you can say e.g. "feat(wnfs-common)" or "feat(wnfs-wasm)" to indicate that it's only a change in a certain crate)

[matheus23]

This needs conflicts resolved. Then I'd give it a look, we can merge and finally release :)

[matheus23]

✨

I like these!

We learned that some things are useful on its own (SharePayload), rename them and sprinkle them along the API more.
We learned that you shouldn't create seeded keys and directories themselves, but instead seed an asymmetric keypair. Thus making a bunch of RevisionRef stuff obsolete.
We'll continue to learn more about exactly how we should best structure stuff.
I'm pretty confident we're continually improving :)

I'd love to have this merged, so I can do a final rebase of #247 and finally have a review & merge on that too.