Client-side-validation v0.5

This version for the first time represents reference implementation for R1 version of client-side-validation standards, organized in separate sublibraries/rust crates:

• 📦 Strict encoding (LNPBP-7 and LNPBP-42 standards): binary standard of encoding client-side-validated data and network addresses.
• 📦 Commit-verify client-side-validation-specific APIs, including
  • consensus commitments (part of LNPBP-8 standard)
  • multi-commitments (LNPBP-4 standard)
  • merklization for client-side-validation (LNPBP-81 standard)
• 📦 Single-use-seals API (LNPBP-8 standard)
• 📦 Client-side-validation API from the library root, linking those components together according to LNPBP-9 standard.

The library represents generalized client-side-validation APIs, abstracted from its bitcoin-specific applications and RGB, with detailed documentation and test coverage.

This release finalizes all pending work on client-side-validation and is a final release before the library will move to v1.0 version, which will be released upon the final audit of the current release. This will define a milestone when client-side-validation can be used in production environments.

The library is located at https://crates.io/crates/client_side_validation. Library documentation 📖 is at https://docs.rs/client_side_validation/0.5.0/

Supported & tested platforms: Linux (Ubuntu 20.04 and Ubuntu 21.04), Mac OS (Mac OS Big Sur and Mac OS Catalina), Windows 2020 Server.