oeqa/sdk: Add case and context modules for the SDK component

oeqa/sdk: Add case and context modules for the SDK component

Adds case and context modules for SDK based on oetest.py old code.

Enables SDK Test component usage with oe-test, the SDK Test component
adds command line options for specify sdk installed dir, sdk environment
and target/hosts maniftest.

[YOCTO #10599]

(From OE-Core rev: 19e875dd81c42841666e6db5f6b665b4e1cddfe6)

Signed-off-by: Aníbal Limón <anibal.limon@linux.intel.com>
Signed-off-by: Mariano Lopez <mariano.lopez@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>