fix(input)!: Consolidate Input traits

[epage]

This is modeled off of rust-bakery/nom#1612 and rust-bakery/nom#1610 with a mix of combine::Stream.

• Chose Token, like combine, as that is the term I've been generally
  standardizing on and is clearer in intent than Item
• Baking in Slice support as that is important for wrapper types. I chose
  Slice over combines Range as this is more focused on Rust integration,
  rather than grammar integration, and we are generally using slice. This helped simplify things having next_slice return Input::Slice rather than having to do into_output().
• next_token is really what some of nom's existing traits are trying to do
  but awkwardly. combine does this through StreamOnce::uncons
• iter_offsets instead of iter_tokens as the only time you should care
  about the tokens, you should be looking at the offsets unless using something
  like AsBytes.
• next_slice is a parallel to next_token but the return type differs as the
  lookup is done in a different function call. I'm tempted to add an
  unchecked variant but I want to benchmark first.

I considered following combine and doing separate InputToken and
InputSlice traits but figured we'd see how this goes first.

As part of this, a streaming bug in hex_u32 was fixed

BREAKING CHANGE: Input traits changed for most parsers and the old traits were removed

[github-advanced-security]

clippy found more than 10 potential problems in the proposed changes. Check the Files changed tab for more details.

[coveralls]

Pull Request Test Coverage Report for Build 4068391968

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

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Details

• 380 of 574 (66.2%) changed or added relevant lines in 13 files are covered.
• 31 unchanged lines in 8 files lost coverage.
• Overall coverage increased (+1.3%) to 58.094%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/bits/mod.rs	4	5	80.0%
src/parser.rs	2	4	50.0%
src/combinator/mod.rs	12	19	63.16%
src/bytes/complete.rs	52	65	80.0%
src/character/complete.rs	72	90	80.0%
src/number/streaming.rs	32	51	62.75%
src/number/complete.rs	30	52	57.69%
src/character/streaming.rs	66	92	71.74%
src/bytes/streaming.rs	30	60	50.0%
src/input.rs	49	105	46.67%

Files with Coverage Reduction	New Missed Lines	%
src/combinator/mod.rs	1	58.2%
src/number/streaming.rs	1	62.55%
src/bytes/streaming.rs	2	54.02%
src/character/mod.rs	2	35.23%
src/character/streaming.rs	2	74.24%
src/bytes/complete.rs	3	68.02%
src/parser.rs	5	41.32%
src/input.rs	15	37.88%

Totals
Change from base Build 4048669216:	1.3%
Covered Lines:	1676
Relevant Lines:	2885

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💛 - Coveralls