Unify to expose symbol for Field

[chokobole]

Issue type

Feature Request

Current behavior?

Some exposes field type as F and others as Field.

tachyon/tachyon/crypto/hashes/sponge/sponge.h

Line 71 in d94cd9a

using F = typename CryptographicSpongeTraits<Derived>::F;

tachyon/tachyon/crypto/commitments/univariate_polynomial_commitment_scheme.h

Line 19 in d94cd9a

using Field = typename VectorCommitmentScheme<Derived>::Field;

Expected Behavior?

Unifying how to expose type for Field