oeqa/selftest: Add rust selftests

oeqa/selftest: Add rust selftests

The patch implements Rust testing framework similar to other selftest,
specifically the gcc selftest in OE. It uses the client and server
based method to test the binaries for cross-target on the image.
The test framework is a wrapper around the Rust build system as ./x.py
test. It tests many functionalities of Rust distribution like tools,
documentation, libraries, packages, tools, Cargo, Crater etc.
Please refer the following link for detailed description of Rust
testing:-
https://rustc-dev-guide.rust-lang.org/tests/intro.html#tool-tests

To support the rust tests in oe-core, the following functions were
added:-
setup_cargo_environment(): Build bootstrap and some early stage tools.
do_rust_setup_snapshot(): Install the snapshot version of rust binaries.
do_configure(): To generate config.toml
do_compile(): To build "remote-test-server" for qemu target image.

Approximate Number of Tests Run in the Rust Testsuite :- 18000
Approximate Number of Tests that FAIL in bitbake environment :- 100-150
Normally majority of the testcases are present in major folder "test/"
It contributes to more than 80% of the testcases present in Rust test
framework. These tests pass as expected on any Rust versions without
much fuss. The tests that fail are of less important and contribute to
less than 2% of the total testcases. These minor tests are observed to
work on some versions and fail on others. They have to be added, ignored
or excluded for different versions as per the behavior.
These tests have been ignored or excluded in the Rust selftest
environment to generate success of completing the testsuite.

These tests work in parallel mode even in the skipped test mode as
expected. Although the patch to disable tests is large, it is very simple
in that it only disables tests. When updating to a newer version of Rust,
the patch can usually be ported in a day.

Tested for X86, X86-64, ARM, ARM64 and MIPS64 on Ubuntu 22.04.
Signed-off-by: pgowda <pgowda.cve@gmail.com>
Signed-off-by: Vinay Kumar <vinay.m.engg@gmail.com>
Signed-off-by: Yash Shinde <yashinde145@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>