Deprecate soroban-rpc and publish stellar-rpc-client

[psheth9]

What

Rename soroban-rpc to soroban-rpc-crate and also remove outdated soroban-tools refs

Note crate.io is immutable repository so In order to rename we are following these steps:

**New plan:

• Remove soroban-rpc crate entirely
• Publish new stellar-rpc-client crate (cloned from soroban-rpc)**

Old plan: This could have introduced breaking change so avoided !!

• Update readme in soroban-rpc to redirect users to new stellar-rpc-client crate, remove everything else
• publish soroban-rpc and verify crates.io
• publish stellar-rpc-client and verify crates.io

Why

See #84 it had created lot of confusion when referring to soroban-rpc client crate as sometimes people percieve it as soroban-rpc service and not client crate. we are just better off with renaming to soroban-rpc-client !!

Known limitations

We might need to update any dependent repositories or downstream components !!

[Shaptic]

I really don't have a strong opinion on this whatsoever but maybe something like rs-rpc-sdk would deliver more information to match things like js-stellar-sdk/java-stellar-sdk/rs-soroban-sdk?

[psheth9]

@Shaptic Agreed but I think we would be doing that if we actually move out this crate to its own repo. Suggestion from Lei here