perf: websocket grid connectivity for all internode communication (#18461)

This PR adds a WebSocket grid feature that allows servers to communicate via 
a single two-way connection.

There are two request types:

* Single requests, which are `[]byte => ([]byte, error)`. This is for efficient small
  roundtrips with small payloads.

* Streaming requests which are `[]byte, chan []byte => chan []byte (and error)`,
  which allows for different combinations of full two-way streams with an initial payload.

Only a single stream is created between two machines - and there is, as such, no
server/client relation since both sides can initiate and handle requests. Which server
initiates the request is decided deterministically on the server names.

Requests are made through a mux client and server, which handles message
passing, congestion, cancelation, timeouts, etc.

If a connection is lost, all requests are canceled, and the calling server will try
to reconnect. Registered handlers can operate directly on byte 
slices or use a higher-level generics abstraction.

There is no versioning of handlers/clients, and incompatible changes should
be handled by adding new handlers.

The request path can be changed to a new one for any protocol changes.

First, all servers create a "Manager." The manager must know its address 
as well as all remote addresses. This will manage all connections.
To get a connection to any remote, ask the manager to provide it given
the remote address using.

```
func (m *Manager) Connection(host string) *Connection
```

All serverside handlers must also be registered on the manager. This will
make sure that all incoming requests are served. The number of in-flight 
requests and responses must also be given for streaming requests.

The "Connection" returned manages the mux-clients. Requests issued
to the connection will be sent to the remote.

* `func (c *Connection) Request(ctx context.Context, h HandlerID, req []byte) ([]byte, error)`
   performs a single request and returns the result. Any deadline provided on the request is
   forwarded to the server, and canceling the context will make the function return at once.

* `func (c *Connection) NewStream(ctx context.Context, h HandlerID, payload []byte) (st *Stream, err error)`
   will initiate a remote call and send the initial payload.

```Go
// A Stream is a two-way stream.
// All responses *must* be read by the caller.
// If the call is canceled through the context,
//The appropriate error will be returned.
type Stream struct {
	// Responses from the remote server.
	// Channel will be closed after an error or when the remote closes.
	// All responses *must* be read by the caller until either an error is returned or the channel is closed.
	// Canceling the context will cause the context cancellation error to be returned.
	Responses <-chan Response

	// Requests sent to the server.
	// If the handler is defined with 0 incoming capacity this will be nil.
	// Channel *must* be closed to signal the end of the stream.
	// If the request context is canceled, the stream will no longer process requests.
	Requests chan<- []byte
}

type Response struct {
	Msg []byte
	Err error
}
```

There are generic versions of the server/client handlers that allow the use of type
safe implementations for data types that support msgpack marshal/unmarshal.

go.mod

@@ -26,13 +26,14 @@ require (
 	github.com/go-ldap/ldap/v3 v3.4.6
 	github.com/go-openapi/loads v0.21.2
 	github.com/go-sql-driver/mysql v1.7.1
+	github.com/gobwas/ws v1.3.1-0.20231030152437-516805a9f3b3
 	github.com/golang-jwt/jwt/v4 v4.5.0
 	github.com/gomodule/redigo v1.8.9
 	github.com/google/uuid v1.3.1
 	github.com/hashicorp/golang-lru v1.0.2
 	github.com/inconshreveable/mousetrap v1.1.0
 	github.com/json-iterator/go v1.1.12
-	github.com/klauspost/compress v1.17.1
+	github.com/klauspost/compress v1.17.3
 	github.com/klauspost/cpuid/v2 v2.2.5
 	github.com/klauspost/filepathx v1.1.1
 	github.com/klauspost/pgzip v1.2.6
@@ -78,7 +79,7 @@ require (
 	github.com/secure-io/sio-go v0.3.1
 	github.com/shirou/gopsutil/v3 v3.23.9
 	github.com/tidwall/gjson v1.17.0
-	github.com/tinylib/msgp v1.1.8
+	github.com/tinylib/msgp v1.1.9-0.20230705140925-6ac204f0b4d4
 	github.com/valyala/bytebufferpool v1.0.0
 	github.com/xdg/scram v1.0.5
 	github.com/zeebo/xxh3 v1.0.2
@@ -138,6 +139,8 @@ require (
 	github.com/go-openapi/strfmt v0.21.7 // indirect
 	github.com/go-openapi/swag v0.22.4 // indirect
 	github.com/go-openapi/validate v0.22.1 // indirect
+	github.com/gobwas/httphead v0.1.0 // indirect
+	github.com/gobwas/pool v0.2.1 // indirect
 	github.com/goccy/go-json v0.10.2 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect