Removing shielded address prefixes map

[EvgenKor]

Shielded addresses almost always contain a prefix that indicates the destination pool or generic address type (zkbob: prefix). The Rust library is fully responsible for generating, parsing, and validating addresses. To introduce a new pool, changes must be made to the hardcoded map located in the libzkbob-rs library. However, this approach is not very convenient.

For the simplicity of deploying a new pool, the hardcoded map should be removed from the libzkbob-rs library, moved to a higher level (zkbob-client-js), and made customizable from the application side. The Rust library will no longer have knowledge of address prefixes; it will only deal with the base58 block of the address.

The following changes are introduced by this pull request:

• Hardcoded prefixes are fully removed from libzkbob-rs.
• The libzkbob-rs::address:parse_address function now parses only the last address block (base58) and ignores any prefixes
• The network name should not be passed in the UserAccount constructor in libzkbob-rs-wasm
• Methods generate_universal_address_for_seed, validate_universal_address, and assemble_universal_address are added to work with generic addresses. Associated methods without the universal keyword work with pool-specific addresses only.

Wasm libraries were published as a beta on npm.js (st, mt)

This PR closes #75

Associated PRs:

• Customizable shielded addresses prefix map zkbob-client-js#172
• Ability to add custom address prefix zkbob-console#100