This commit introduces a new build property, __OPTIONAL_REQUIRES_MODE,
and uses it to either defer or link immediately, optional requirements
to components that request such linkage via the
idf_component_optional_requires() function in build system v2. The
DEFERRED mode is intended for single-binary projects where in the linking
of optional components happens after the library target is created the
dependency graph is available to the build system, thereby allowing it to
behave like the v1 version of the function.
700c86d0c9