Moved DigestItem impl to impl_outer_log (#932)

* moved DigestItem impl to impl_outer_log

* Enable backtrace collecting on the CI

* internal module is not required in impl_outer_log

* Revert "internal module is not required in impl_outer_log"

This reverts commit 54304469.

* Revert "moved DigestItem impl to impl_outer_log"

This reverts commit 8872bbee.

* Revert "Revert "moved DigestItem impl to impl_outer_log""

This reverts commit 47afd596.

* Revert "Revert "internal module is not required in impl_outer_log""

This reverts commit 9ae64001.

* More diagnostics

* check if only 1 test fails

* test is back + some "traces"

* removed some traces

* removed "traces"