Add nomad v1 primitives

[luketchang]

Adds necessary Nomad primitives to Avail

• Moves Avail-specific primitives into its own crate primitives/avail
• Adds primitives/nomad which contains:
  • merkle: light merkle tree implementation
  • signature: Ethereum-specific ECDSA signature implementation
  • nomad-core: core message and update types
  • nomad-base: abstraction around Nomad updater and domain-specific info

[MiguelDD1]

Casting from a larger integer to a smaller integer (e.g. u32 -> u8) will truncate.
If that is not safe, pls use u8::try_from(src.v) instead.

[luketchang]

This is safe because sig.v can only ever be 27 or 28 here. Regarding EIP-155 (which isn't relevant because this signature is only for attestations not txs), this is only applied for transaction signing and this happens after the fact (after signature is created, you manually change the v value)

[luketchang]

Added comment above line to clarify

[codecov-commenter]

Codecov Report

Base: 46.96% // Head: 44.91% // Decreases project coverage by -2.05% ⚠️

Coverage data is based on head (a38bd88) compared to base (40145ca).
Patch coverage: 64.92% of modified lines in pull request are covered.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop      #79      +/-   ##
===========================================
- Coverage    46.96%   44.91%   -2.06%     
===========================================
  Files           44       61      +17     
  Lines         9815    11509    +1694     
===========================================
+ Hits          4610     5169     +559     
- Misses        5205     6340    +1135     

Impacted Files	Coverage Δ
primitives/avail/src/asdr.rs	87.50% <ø> (ø)
...imitives/avail/src/asdr/app_unchecked_extrinsic.rs	73.04% <ø> (ø)
primitives/avail/src/asdr/data_lookup.rs	91.66% <ø> (ø)
primitives/avail/src/asdr/get_app_id.rs	100.00% <ø> (ø)
primitives/avail/src/header.rs	48.44% <0.00%> (ø)
primitives/avail/src/kate_commitment.rs	43.24% <ø> (ø)
primitives/avail/src/lib.rs	11.11% <ø> (ø)
primitives/avail/src/traits.rs	7.08% <0.00%> (ø)
primitives/nomad/merkle/src/error.rs	7.56% <2.94%> (ø)
primitives/nomad/merkle/src/lib.rs	14.28% <14.28%> (ø)
... and 19 more

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[aterentic-ethernal]

@luketchang , thanks for contribution, Ill merge this PR. Just small note, if possible, lets clean up top level dependencies in next PRs.