feat: add support for bbs-signatures library

[haardikk21]

Solves #57

Description

Removes the dependency on node-bbs-signatures and adds a dependency on bbs-signatures which has the node fallback built in now.

• Tests for the changes have been added (for bug fixes / features)
• The commit message(s) follow conventional commits
• Documentation has been added / updated (for bug fixes / features)
• Changes follow the contributing document.

Motivation and Context

To allow this library to run in non-node environments (browser, wasm, non-wasm e.g. react native)

Does this PR introduce a breaking change?

• Yes
• No

Which merge strategy will you use?

• Squash
• Rebase (REVIEW COMMITS)

[haardikk21]

Tests are passing on local. They're failing here because the latest unstable release of bbs-signatures on npm does not include the latest build which has the node fallback. On local, I built it myself and copied over the lib folder to node_modules

Looks like the actual issue was just to do with the heap overflow. The latest commit should fix that.

[haardikk21]

Looks like we faced the same issue after the latest commit as described here - mattrglobal/bbs-signatures#35

Will resolve using the workaround here - https://github.com/mattrglobal/bls12381-key-pair/pull/19/files#diff-2d0cd5d10b9604941c38c6aac608178aR7

[haardikk21]

Unable to reproduce the errors being faced in the github workflow runner on my local. Will be doing some debugging on here directly. We can squash the commits later during merge.

[haardikk21]

The tests are passing fine now. We believe the coverage is failing because this is a PR from my fork of the project, and the Github secret token is not being shared with my fork.
@tplooker can we merge?