Murisi/masp

[murisi]

Implemented the parsing of MASP Transactions and Builders. Some notes:

• The code was generated by running a C parser generator on the following Borsh schema: masp_borsh_schema.txt . The format's documentation can be found here.
• The generator calls mem_alloc to support parsing variable length arrays, but this dependency should be easily removable if upper bounds can be established on the vectors occurring in the serializations.
• More types of Namada addresses can now be parsed including internal Ethereum addresses. Full parsing of addresses is required to be able to decode AssetTypes.
• The test vectors have been temporarily filtered to include only MASP transactions since that is the focus of this branch. However it should still support all test vectors from Ledger app v0.0.18.