[backport#14618] rpc: Make HTTP RPC debug logging more informative

Summary:
ab8c6f24d28ea1d1e6258cf316b4b97a0baf2377 Add SAFE_CHARS[SAFE_CHARS_URI]: Chars allowed in URIs (RFC 3986) (practicalswift)
991248649b76a5a071e1360a700f3e2ecf3e1e1f rpc: Make HTTP RPC debug logging more informative (practicalswift)

Pull request description:

• Make HTTP RPC debug logging more informative
• Avoid excessively large log messages (which could theoretically fill up the disk) when running with debug option -debug=http

Tree-SHA512: 9068862fb7d34db1e12e6b9dde78b669b86c65b4fed3ea8c9eb6c35310d77fd12b16644728fd7e9fbf25059d25114bded9e061eb3de649d8847486ec42041ce9

This is a backport of Core PR14618

Test Plan:

ninja check

Reviewers: O1 Bitcoin ABC, #bitcoin_abc, deadalnix

Reviewed By: O1 Bitcoin ABC, #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D5747