Add Portuguese support

[WesleyBatista]

Description of change

Add Portuguese support by bringing the official wordlist from bitcoin/bips repo, through src/keys/bip39.pt.rs and duplicating necessary portions of the codebase

• tests/test_vectors/bip39/trezorPT.sh is an adapted copy of trezor.sh in same directory, main difference being the hash in line 15
• tests/fixtures/bip39_pt.rs was generated with output from trezorPT.sh

Links to any relevant issues

Related: #219

Type of change

Choose a type of change, and delete any options that are not relevant.

• Bug fix (a non-breaking change which fixes an issue)
• Enhancement (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Fix

How the change has been tested

cargo test --features=bip39-pt

Change checklist

Add an x to the boxes that are relevant to your changes, and delete any items that are not.

• I have followed the contribution guidelines for this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes