devtool: export: new plugin to export the devtool workspace

devtool: export: new plugin to export the devtool workspace

By default, exports the whole workspace (all recipes) including the source code.
User can also limit what is exported with --included/--excluded flags. As
a result of this operation, a tar archive containing only workspace metadata
and its corresponding source code is created, which can be properly imported
with 'devtool import'.

https://bugzilla.yoctoproject.org/show_bug.cgi?id=10510

[YOCTO #10510]

Signed-off-by: Leonardo Sandoval <leonardo.sandoval.gonzalez@linux.intel.com>
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>