Split libvcx, deprecate libvcx::api_c, libvcx-ios, libvcx-java

[Patrik-Stas]

Split the 2 modules of libvcx: api_c,api_vcx into 2 separate crates:

• api_c -> libvcx

• api_vcx -> libvcx_core

• Deprecate (unless willing maintainers would be found) libvcx and ios and java wrapped built on top of it

Naming can be tweaked.

[Patrik-Stas]

Additionally few more ideas, this can perhaps deserve its own issue, but for now just throwing it here:

• We could do bit of reorg after that to clean up the root directory of the project. Instead of having

- libvcx
- libvcx_core
- wrappers

I'd suggest we have just 1 root directory libvcx where we can place all of these. Even wrappers, as they represent libvcx wrappers, built around the handles architecture.

• Following this approach in UniFFI Proof of Concept #737 we could then create new top level directory
  unifii_vcx (or something like that) and place there the core unifii based wrapper alongside demos built on top of that.

• And one more point: instead of having agents in root which contain both "libvcx" based agent and aries-vcx based agent, we could reorg them accordingly too (move libvcx based node agent under libvcx directory)

To conclude, something like this would be final result:

agents
   - aries-vcx-agent
libvcx
   - libvcx
   - libvcx_core
   - wrappers
       - vcx_napi_rs
       - ....
   - agents
      - vcxagenct_core
unifii_vcx
  - core
  - demos