Client side routing implementation (#205)

* Basic implementation of client side routing:
 - Use round-robin balancing
 - Store routing table in a Dashmap to allow fast concurrency
 - Perform the update of the routing table using a simple mutex on the TTL of the table itself
 - read/write mode is propagated into the RUN command
 - Bolt scheme in pools to allow direct connections with no routing to provided servers

* Address most of the comments

* Remove Default implementation for Database structure

* Remove debug message

* - Use Instant for creation time in the connection registry
- Lock the creation_time

* Remove call to ok()

* Use compare for versions >= 4.4

* Renaming Normal -> Direct

* Remove run_read since it is essentially useless

* Formatting

* Remove zeroes in supported versions

Author: madchicken

ci/Cargo.lock.min

@@ -31,6 +31,7 @@ unstable-bolt-protocol-impl-v2 = [
 backoff = { version = "0.4.0", features = ["tokio"] }
 bytes = { version = "1.5.0", features = ["serde"] }
 chrono-tz = "0.10.0"
+dashmap = "6.1.0"
 delegate = "0.13.0"
 futures = { version = "0.3.0" }
 log = "0.4.0"

ci/Cargo.lock.msrv

@@ -6,6 +6,7 @@ mod hello;
 mod pull;
 mod reset;
 mod rollback;
+mod route;
 
 pub use commit::Commit;
 pub use discard::Discard;