chore(deps): use helios 0.5.4 && enable rustls

[sergey-melnychuk]

Use Helios 0.5.4 (tag) instead of raw commit.
Add rustls feature to reqwest (closes #555).

Extra:

• some chores (avoid .clone() and panic!)
• remove references to feat: sync from proven root #550
• fmt

[sergey-melnychuk]

Confirming that this PR closes #555. With mimtproxy, a proxied call to Starknet fails:

{"jsonrpc":"2.0","error":{"code":-32601,"message":"error sending request for url (https://starknet-mainnet.g.alchemy.com/v2/<snip>): error trying to connect: error:0A000086:SSL routines:tls_post_process_server_certificate:certificate verify failed:ssl/statem/statem_clnt.c:2091: (unable to get local issuer certificate)"},"id":0}

Still unclear how exactly #555 was reproduced.