sui-json-rpc-api: remove the crate

The JSON-RPC client traits it defined no longer have a client to serve, now
that the `sui-sdk` JSON-RPC client is gone. Its last remaining user was the
transactional test runner, which took the default event page size from it;
that is now a local constant in the test adapter. A couple of comments in
`sui-rpc-benchmark` that pointed at the crate's source files now name the
JSON-RPC method groups instead.

Author: bmwill

Cargo.lock

@@ -137,7 +137,6 @@ members = [
     "crates/sui-indexer-alt-schema",
     "crates/sui-inverted-index",
     "crates/sui-json",
-    "crates/sui-json-rpc-api",
     "crates/sui-json-rpc-types",
     "crates/sui-keys",
     "crates/sui-kv-rpc",
@@ -696,7 +695,6 @@ sui-indexer-alt-reader = { path = "crates/sui-indexer-alt-reader" }
 sui-indexer-alt-schema = { path = "crates/sui-indexer-alt-schema" }
 sui-indexer-alt-object-store = { path = "crates/sui-indexer-alt-object-store" }
 sui-json = { path = "crates/sui-json" }
-sui-json-rpc-api = { path = "crates/sui-json-rpc-api" }
 sui-json-rpc-types = { path = "crates/sui-json-rpc-types" }
 sui-keys = { path = "crates/sui-keys" }
 sui-inverted-index = { path = "crates/sui-inverted-index" }