Test Details Overview

Rename the RPC server classes and move the HTTP test client to test_common (#5172)

* Rename `nano::rpc` to `nano::rpc_server`

The class is the HTTP listener that accepts RPC connections and hands
requests to a handler. Naming it after the protocol made it read like
the RPC API itself and clashed with the `nano::rpc_*` config and handler
types around it. This is a mechanical rename, including the header and
source files, with no behavioural change.

* Rename `rpc_handler` to `rpc_dispatcher`

The class parses the JSON envelope of one request, enforces control
level access and hands the request to a `rpc_handler_interface`
backend. Calling it a handler made it read as the same layer as the
backend contract and its implementations. This is a mechanical rename,
including the header and source files.

* Move the HTTP test client to `test_common`

`test_response` is a plain JSON over HTTP client with no knowledge of
the RPC API, but it lived in `rpc_test` and pulled in the IPC server
and request processor headers it never used. It moves to `test_common`
with only the includes it needs, so the upcoming `rpc_server` unit
tests in the core suite can drive the server with the same client the
RPC API tests use.

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Type: commit

Hash: eb10f451324375d7b4fcf21126a0c24a2e091d55

Created: yesterday

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gr0v1ty/nano-node:eb10f451324375d7b4fcf21126a0c24a2e091d55