Harmonize the dependencies to use a single TLS stack

[mzabaluev]

Summary

Both native-tls/openssl and rustls are present in the dependency tree.

Problem Definition

As of 2e8d839, there are the following dependency chains:

ibc ⭢ ibc-proto ⭢ tonic ⭢ tokio-rustls ⭢ rustls
ibc ⭢ tendermint-light-client ⭢ tendermint-rpc ⭢ hyper-proxy ⭢ hyper-tls ⭢ native-tls ⭢ openssl

Use of two TLS stacks bloats up the binary size and increases build time.
The need to link the foreign OpenSSL library complicates the build (see #1569).

Proposal

Choose one of the stacks and make sure all crates in the dependency tree use it.

Looking at the state of the dependency tree, tendermint-rpc is an outlier, pulling in OpenSSL perhaps by oversight: hyper-proxy can be switched to rustls, furthermore, tendermint-rpc itself also depends on hyper-rustls.

Acceptance Criteria

native-tls, openssl are not present in the dependency tree.

---

For Admin Use

• Not duplicate issue
• Appropriate labels applied
• Appropriate milestone (priority) applied
• Appropriate contributors tagged
• Contributor assigned/self-assigned

[mzabaluev]

Waiting for the next release of tendermint-rs to solve this issue.