Add MeTTa DAS Bus Client

[arturgontijo]

DO NOT MERGE IT!!! As we plan to have a tag/version of the DAS repo to use it here (currently using master)

This PR adds a new built-in module called das that uses the metta-bus-client rust package to send pattern matching queries to a DAS Service Bus.

In order to test it, one could follow the steps from Setup DAS locally and then:

cargo build --release --features=das

Then run the MeTTa REPL binary:

./target/release/metta-repl 
Visit https://metta-lang.dev/ for tutorials.
Execute !(help!) to get list of the standard library functions.
> !(import! &self das)
[()]
> !(bind! &das (new-das! (localhost:8080) (localhost:35700)))
[()]
> !(match &das (Similarity "human" $S) ($S))
[(a408f6dd446cdd4fa56f82e77fe6c870), (3225ea795289574ceee32e091ad54ef4), (181a19436acef495c8039a610be59603)]
> 

@vsbogd let me know if I'm in the right direction about adding new modules here.

[vsbogd]

Last couple of things I missed on the previous review.

[arturgontijo]

Hey @vsbogd sorry for the huge delay on this one...We finally got a version tag that exposes the necessary code for this module.
When you get a chance, please do another review round here.

[vsbogd]

Thanks @arturgontijo , looks good to me and I am ready to merge it.

There are two alternatives:

1. make it available by default, then it should be added into default feature list in Cargo.toml
2. keep it optional, then I would add it as a default into Release builds as users would expect it is present

I don't see why we cannot make it default choice (i.e. option (1)), but I would like to know your opinion on this. Option (2) can be implemented as a separate PR.

For the option (2) there are two places to edit:

• first one is the Dockerfile

  hyperon-experimental/Dockerfile

  Line 32 in 500d777

  RUN cargo build --features python,git --release

  to add it into the Docker metta-repl
• second one is more tricky add it as an option to the CMake files, see

  hyperon-experimental/python/CMakeLists.txt

  Line 4 in 500d777

  option(GIT "Adds git features to hyperon library; requires OpenSSL and Zlib" ON)

  and all usages of the 'GIT' in code.

[vsbogd]

In any case after the change it is worth to check that DAS integration is a part of the Release build i.e. try building docker (see https://github.com/trueagi-io/hyperon-experimental#docker) and try releasing Python binaries locally (https://github.com/trueagi-io/hyperon-experimental/blob/main/docs/DEVELOPMENT.md#how-to-release-python-distribution-packages-locally).

[vsbogd]

BTW probably this PR obsoletes:

• https://github.com/trueagi-io/hyperon-experimental/tree/main/python/integration
• https://github.com/trueagi-io/hyperon-experimental/tree/main/python/hyperon/exts/das_gate

@CICS-Oleg , what do you think?

[CICS-Oleg]

BTW probably this PR obsoletes:

https://github.com/trueagi-io/hyperon-experimental/tree/main/python/integration
https://github.com/trueagi-io/hyperon-experimental/tree/main/python/hyperon/exts/das_gate

Yeah, It's definitely obsolete.

[arturgontijo]

make it available by default, then it should be added into default feature list in Cargo.toml

@vsbogd I vote for making it default (as this option seems more simple then 2, and we can change that in future if needed).

check that DAS integration is a part of the Release build

Will do and let you know