refactor(crypto): remove validation rules and validator

[faustbrian]

Proposed changes

A bunch of old and unused code was left over from constant changes and refactoring of the crypto validation parts. I removed the Validator class as I couldn't find any place where it was used as we always use the Joi alias we export which is an instance of the Engine class.

Resolves #2015
Resolves #2020

Types of changes

• Refactoring (improve a current implementation without adding a new feature or fixing a bug)

Checklist

• I have read the CONTRIBUTING documentation
• Lint and unit tests pass locally with my changes

[codecov-io]

Codecov Report

Merging #2021 into develop will decrease coverage by 0.4%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop    #2021      +/-   ##
===========================================
- Coverage     73.1%   72.69%   -0.41%     
===========================================
  Files          386      373      -13     
  Lines         8351     8252      -99     
  Branches      1193     1195       +2     
===========================================
- Hits          6105     5999     -106     
- Misses        2213     2218       +5     
- Partials        33       35       +2

Impacted Files	Coverage Δ
...pto/src/validation/extensions/transactions/base.ts	100% <ø> (ø)	⬆️
...es/crypto/src/validation/validators/transaction.ts	100% <100%> (ø)	⬆️
...ages/crypto/src/validation/extensions/bignumber.ts	100% <100%> (ø)	⬆️
packages/crypto/src/validation/validator.ts	100% <100%> (ø)	⬆️
.../crypto/src/handlers/transactions/multi-payment.ts	30% <0%> (-70%)	⬇️
packages/core-test-utils/src/helpers/container.ts	0% <0%> (ø)	⬆️
packages/core-test-utils/src/generators/wallets.ts	14.28% <0%> (ø)	⬆️

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