`from_xrpl` should not accept snake_case dict keys

[ckeshava]

BaseModel.from_xrpl method should not accept snake_case keys in dictionary input.

Fix #689 . You can find more context in the discussion pertaining to this issue.

I have used a regular expression matches for snake_case. If you have any other ideas for detecting non-camelCase input formats, let me know. There appears to be a variety of solutions for this problem, but all of them have slight differences in their behavior.

High Level Overview of Change

Context of Change

Type of Change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [x] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Refactor (non-breaking change that only restructures code)
• [x] Tests (You added tests for code that already exists, or your new feature included in this PR)
• [ ] Documentation Updates
• [ ] Release

Did you update CHANGELOG.md?

• [ ] Yes
• [x] No, this change does not impact library users Do external users use from_xrpl method? I believe they use from_dict (hasn't been modified) which internally makes a call to from_xrpl

Test Plan

[ckeshava]

The integration and snippet tests are not reliable. I'm observing these errors: (Integration Test Python 3.8): xrpl.asyncio.wallet.wallet_generation.XRPLFaucetException: Unable to fund address with faucet after waiting 40 seconds

Snippet test error: httpx.HTTPStatusError: Server error '502 Bad Gateway' for url 'https://faucet.altnet.rippletest.net/accounts'

[ckeshava]

@justinr1234 @khancode can you please review this at your convinience?

[ckeshava]

I have updated the regular-expression which is used to invalidate inputs in BaseModel. This was required after the introduction of the AMM feature. (AMM introduced a new type of key Amount2, with an integer in its wake -- this was breaking the regexp)

If anyone has objections pertaining to it, please let me know. It is not related to the changelist of this PR.