Evaluate conversion functions for all crates.

[heemankv]

With continuous development of the orchestrator we have come to notice that
the amount of conversion functions have increases a lot,
especially in the ethereum-settlement-client crate, we would ideally want to reduce them and implement generics.
(instead of implement a method for both size 32 and size 48, we can use a generic maybe)

[heemankv]

Code betterment through various PRs have made this issue insignificant,
eg : ethereum-settlement-client was refactored by PR #81.
Overall the codebase as of now has conversion functions defined for their specific scope, with no excess.