Unify secp256k1_zkp usage

[andrewkozlik]

Resolves https://github.com/trezor/trezor-firmware/issues/1864.

• Moves the dispatching of zkp_ecdsa_*() vs. ecdsa_*() functions to ecdsa.c to simplify usage (no more #ifdefs for this in core and legacy code).
  • As a side-result the above change automatically causes crypto/bip32.c to use the secp256k1_zkp functions for public key derivation and signing without any code changes in bip32.c.
  • I renamed the trezor-crypto native implementations of the relevant ecdsa_* functions to tc_ecdsa_* so that they can be tested independently in the crypto tests.
  • It seems that the usage of secp256k1_zkp in bip32.c causes a different amount of data to be taken from the PRNG, which in turn causes the PIN matrix layouts to change, hence the changes to UI tests.
• Implements Ethereum and EOS canonical ECDSA signing using the secp256k1_zkp library.
  • Some of the EOS signatures (10/16) had to be changed, because the signing retry works differently than in the trezor-crypto native implementation.
  • Signing of EOS operations will need to be tested extensively by QA!