Refactor consensus/types (#7827)

Organize and categorize `consensus/types` into modules based on their relation to key consensus structures/concepts.
This is a precursor to a sensible public interface.

While this refactor is very opinionated, I am open to suggestions on module names, or type groupings if my current ones are inappropriate.


Co-Authored-By: Mac L <mjladson@pm.me>

common/eth2/Cargo.toml

@@ -9,6 +9,7 @@ default = ["lighthouse"]
 lighthouse = []
 
 [dependencies]
+context_deserialize = { workspace = true }
 educe = { workspace = true }
 eip_3076 = { workspace = true }
 either = { workspace = true }