Basic optimizations

[Dreyhh]

• The getRecommendedContacts() method currently uses the getSharedSIgners() method which could potentially trigger the decryption of shared signers which is out of the scope of the method, it suffices to fetch the shared signer events.
• The isValidAuthority() call within processKeyAgentsEvents is redundant since the verified key agents filter already guarantees that only the events from authority are fetched.
• The timeout of isNip05Verified() currently is set at 2 seconds by default, this should be fine-tuned to reduce loading times.
• For the kinds that do not have the deletion feature enabled, nor plans to implement it, we should avoid storing the raw events since there is no other use case, this will help to reduce memory usage.
• TBD...