This commit fixes memory leaks in unity tests when the debug option
CONFIG_FREERTOS_USE_LIST_DATA_INTEGRITY_CHECK_BYTES is enabled. The
commit increases the threshold to 1200 bytes from 1024 bytes.
New unity component can be used for testing other applications.
Upstream version of Unity is included as a submodule.
Utilities specific to ESP-IDF unit tests (partitions, leak checking
setup/teardown functions, etc) are kept only in unit-test-app.
Kconfig options are added to allow disabling certain Unity features.
