Miscellaneous Changes: Serialization, additional helper methods, reorg

[jon-chuang]

Description

Miscelaneous changes associated with celo-org merge. Ranging from harmless to API changes. closes: https://github.com/arkworks-rs/algebra/pull/127

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• [x] Targeted PR against correct branch (master)
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• [x] Wrote unit tests
• [x] Updated relevant documentation in the code
• [ ] Added a relevant changelog entry to the Pending section in CHANGELOG.md
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[jon-chuang]

To reviewers:

• Not sure if you'd like for me to refactor further. This is the least cohesive PRs of those to come since I've staged them to build atop one another, and this is the remaining changes that don't have any specific topic it is tied to. However, if you think it would be cleaner to extract the diff of one of the branches jonch/celo-org-... feel free to let me know or to do so yourself.

[Pratyush]

For the serialize changes, we should update the derive macro to additionally incorporate uncompressed_unchecked.

Also, maybe in a follow-up PR, let's make it so that the Serialize and Deserialize traits both have a (de)serialize_with_mode method:

trait CanonicalSerialize {
...
	fn serialize_with_mode<W: Write>(&self, compression: ShouldCompress, writer: W) {
		match compression {
			ShouldCompress::Yes => {
				// do stuff
			},
			ShouldCompress::No => {
				// do other stuff
			}
		}
	}

	// all other methods invoke `serialize_with_mode` with appropriate modes.
}

trait CanonicalDeserialize {
	fn deserialize_with_mode<R: Read>(&self, compression: ShouldCompress, check: ShouldCheck reader: R) -> Result<Self> {
		match compression {
			ShouldCompress::Yes => {
				// do stuff
			},
			ShouldCompress::No => {
				// do other stuff
			}
		}
		if let ShouldCheck::Yes = check {
			// perform checks
		}
		Ok(result)
	}
	
	// all other methods invoke `deserialize_with_mode` with appropriate modes.
}

(I omitted the check from serialize, because AFAIK there are no checks performed during serialization? This means that we remove serialize_unchecked and serialize_uncompressed_unchecked too.)

The reason why we want to add the above API is so that downstream implementers can just implement the logic in one method, instead of in four different ones.

[Pratyush]

@jon-chuang is there anything I can do to help push this forward?