oeqa/sdk/meson: generalise test case

oeqa/sdk/meson: generalise test case

Refactor this test case so the generic "build a meson project" code is
separated out and can be reused.

Also currently meson inside eSDKs only works with fully populated eSDKs,
but our testing uses minimal eSDKS, so skip the test if the eSDK is a
minimal build.  A bug has been filed to resolve this.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>