[Uid] add AbstractUid and interop with base-58/32/RFC4122 encodings

[nicolas-grekas]

Q	A
Branch?	master
Bug fix?	no
New feature?	yes
Deprecations?	no
Tickets	-
License	MIT
Doc PR	-

This PR provides a base AbstractUid class that is shared by Uuid and Ulid.

It adds new methods that provide interoperability between all types of UIDs but also between different encodings of UIDs:

• toBase58() using the bitcoin alphabet - that's 22 chars aka "short-ids" - case sensitive
• toBase32() using Crockford's alphabet - 26 chars ids - case insensitive
• toRfc4122() to represent as a UUID-formatted string - 36 chars

This adds to toBinary() and to fromString(), the latter being able to cope with any of the 4 representations to create any kind of UIDs.

[javiereguiluz]

I don't know the future plans of this component (will we keep adding other popular UIDs?) but this doesn't look future-proof to me. Any method that we add here could look outdated or unused in other future UID generators.

This reminds me to the salt property of password encoders. It was obvious to add it to an interface because every encoder uses it ... until some stopped using it and the interface no longer looked good for modern encoders.

[nicolas-grekas]

All serious id schemes use 128-bit identifiers, which is wide enough to deal with any use cases for the foreseeable future. Then, base58, base32, uuid-format are 3 widely used representation of 128-bit numbers. They fit various needs: 58 bit for compactness, 32 bit for case insensitivity, uuid-format for interop with e.g. DB storages.

My opinion is that all three of them are generic enough to land in the component.

Your comparison with salted-encoders is good: we did add them to the component because that's what ppl were widely using at the time. We don't know the future but we know these encoding schemes are widely used and have good reasons to remain so.

[nicolas-grekas]

will we keep adding other popular UIDs?

UUIDv6 would make sense. I'm not sure about others. I think we should work on integrating with Doctrine before considering other schemes. Then future will tell, there are no plans...

[fabpot]

Can you rebase?

[nicolas-grekas]

Now rebased.

[fabpot]

Thank you @nicolas-grekas.