chore(sidecar): mog unused dependencies with cargo-machete

[merklefruit]

Used cargo-machete to remove unused dependencies in bolt-sidecar

~/bolt/bolt-sidecar ❯ cargo machete
Analyzing dependencies of crates in this directory...
cargo-machete didn't find any unused dependencies in this directory. Good job!

I also took the opportunity to:

• pin leftover unpinned git dependencies
• slightly refactor the sidecar entry binary
• remove reth-rpc-layer dependency by copying a 10-line utility function that uses all alloy types

[mempirate]

Wonder if we need full here

[merklefruit]

if we remove it we'll have to add a bunch of other features in its place, but I haven't tried

[mempirate]

Symbiotic links are failing - ignored them in #407 so can just rebase