oeqa/sdk/cases: Migrate tests to the new OEQA framework

oeqa/sdk/cases: Migrate tests to the new OEQA framework

Summary of the changes:

- Remove auto extend_path using pkgutil at __init__, is not needed.
- Change base class to OESDKTestCase.
- Add td_vars attr to set dependencies of certain variables in test
data.
- Change skips from module level to class level because Test context
  (tc)
now isn't at module level.
- Variable names changes to be consistent (i.e. sdktestdir ->
  sdk_dir).

[YOCTO #10599]

- Don't use bb.utils functions use instead remove_safe and shutil
  for copy files.
- SDKBuildProject pass test data variables instead of call getVar
  inside.

[YOCTO #10231]

(From OE-Core rev: 91cd1ed19a3f34c29cd77eb136036975fe465444)

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>