Also bifurcates prove with prove_plus, and adds a few documentation items.

Also adds a bit more documentation and does a bit more tidying.

It's a notable bandwidth/performance improvement, yet it's not ready. We need a
dedicated Distribution struct which is managed by the wallet and passed in.
While we can do that now, it's not currently worth the effort.

…ates

Abstracts the types used internally.

Also moves the tests from monero-serai to monero-clsag.

Removes usage of dalek-ff-group/multiexp for curve25519-dalek.

Makes compiling in the generators an optional feature.

Adds a structured batch verifier which should be notably more performant.

Documentation and clean up still necessary.

I still don't like the impl of the original Bulletproofs...

Also adds a helper to fetch a transaction's prefix.

Credit to @hinto-janai for adding such sections to their work on documenting
monero-serai in #568.

I have yet to redo the multisig code and the builder. This should be much
cleaner, albeit slower due to redoing work.

This compiles with clippy --all-features. I have to finish the multisig/builder
for --all-targets to work (and start updating the rest of Serai).

Some are _consistently_ failing due to the inputs we attempt to spend being too
young. I'm unsure what's up with that. Most seem to pass _consistently_,
implying it's not a random issue yet some configuration/env aspect.

…er/GuaranteedScanner

Also cleans the Scanner impl.

Guaranteed addresses are in fact guaranteed even with this due to prefixing key
images causing zeroing the ECDH to not zero the shared key.

This was done by requiring the system's usize can represent a certain number.

Unfortunately, this test is still failing.

Finally fixes the lack of decoy candidates failures in CI.

Change made due to a segfault incurred when locally testing.

monero-project/monero#9141 for the upstream.

Adds a minimum XMR fee to the processor and runs fmt.

I'm truly unsure why this is required right now.

If there's no change, the fee is difference of the inputs to the outputs. The
prior code wouldn't check that amount is greater than or equal to the necessary
fee, and returning the would-be change amount as the fee isn't necessarily
helpful.

Now the fee is validated in such cases and the necessary fee is returned,
enabling operating off of that.