Add ws support for DI server

[Kailai-Wang]

Context

As topic. It defines a MaybeServerTlsStream struct to wrap up the plain and rustls stream.

Whether launching a ws or wss server will depend on the value of command line arg --trusted-external-address or --T. Although it's called "external", I reckon it makes little sense when launching an "external" wss server while expecting a ws connection internally in our case. If this value is not present, wss will be used as fallback.

Similarly, --untrusted-external-address will fallback to ws.

Now CI uses ws by default.

I can see a potential refactoring of URL management, e.g. use Url by default, better stucture of "internal" and "external" addresses - but it's out of scope of this PR.

[linear]

P-399 Add ws support for DI server

[Kailai-Wang]

cc @BillyWooo @felixfaisal - once merged and deployed, we need to review the -T setting

[kziemianek]

Should we adjust usage of cli ?

Looks like link_identity fails after this change

kziemianek@kziemianek:~/projects/litentry/litentry-parachain/tee-worker/bin$ ./litentry-cli trusted -d link-identity did:litentry:substrate:0x8eaf04151687736326c9fea17e25fc5287613693c912909cb226aa4794f26a48 did:litentry:evm:0x0D9bFD1f18f5f4FD08247DC54aD3528909c4b3E9 bsc,ethereum
[2024-03-21T11:34:53.433Z ERROR ws::handler] WS Error <Io(Custom { kind: Other, error: "unexpected EOF" })>
thread 'main' panicked at 'Unable to retrieve MRENCLAVE from endpoint: MspcReceiver(RecvError)', cli/src/trusted_command_utils.rs:88:14
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[Kailai-Wang]

Should we adjust usage of cli ?

Looks like link_identity fails after this change

kziemianek@kziemianek:~/projects/litentry/litentry-parachain/tee-worker/bin$ ./litentry-cli trusted -d link-identity did:litentry:substrate:0x8eaf04151687736326c9fea17e25fc5287613693c912909cb226aa4794f26a48 did:litentry:evm:0x0D9bFD1f18f5f4FD08247DC54aD3528909c4b3E9 bsc,ethereum
[2024-03-21T11:34:53.433Z ERROR ws::handler] WS Error <Io(Custom { kind: Other, error: "unexpected EOF" })>
thread 'main' panicked at 'Unable to retrieve MRENCLAVE from endpoint: MspcReceiver(RecvError)', cli/src/trusted_command_utils.rs:88:14
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Thanks!
Now the CLI should use ws by default