* Test: test_add_task_restart_policy_patterns
* Test: test_get_task_restart_policy_patterns
* Test: test_remove_task_restart_policy_patterns
* Test: test_clear_task_restart_policy_patterns
* Test: test_task_resolve_restarts

* TaskRestartPattern
* TaskRestartPolicy
* TaskHistory

* Removed TaskRestartPolicy and TaskHistory
* Added Traceback

* TaskReturnPattern: Confirm that the input pattern is a string type and that it is not empty.
* Traceback: Confirm that the input is a list of strings and that none of them are empty.

Similar to `TaskHub`s, the `TaskRestartPattern` needs additonal hashed
data to uniquely identify it as a Neo4j node (via the gufe key). The
unit tests have been updated to reflect this change.

`statestore` methods have been added to modify the database state:

* add_task_restart_patterns
* remove_task_restart_patterns
* get_task_restart_patterns

Tests were added for each method in the integration tests for the
statestore.

The `add_task_restart_patterns` method now establishes the APPLIES
relationship between the each new pattern and all Tasks ACTIONED
on the corresponding TaskHub.

Added testing for creation of the APPLIES relationship, asserting
the number of created connections over multiple TaskHubs and Tasks.

Further subdivided the test classes.

Additionally added a `set_task_restart_patterns_max_retries` method
for updating the max_retries of a TaskRestartPattern.

"actioning" a Task on a TaskHub with preexisting TaskRestartPatterns
created the APPLIES relationship between them with a num_retries value
of 0. This behavior is tested in the test_action_task function in
the statestore.

When an actioned Task is canceled and also has an APPLIES relationship
with a TaskRestartPattern, APPLIES is removed between the two
nodes.

Removed org, project, and campaign fields since they are not
necessary for the APPLIES relationship.

Setting an actioned Task status to the following statuses now removes
the APPLIES relationship from attached TaskRestartPatterns:

* complete
* invalid
* deleted

NOTE: tests have not been added for this yet

Confirming that changing the status of an actioned Task to any of
the following removes the APPLIES relationship:

* complete
* invalid
* deleted

New statestore method placeholders:
  - add_task_traceback
  - resolve_task_restarts

The compute api will add a Task Traceback and resolve restarts for
returned failed Tasks.

When a list of restart patterns are added, restarts are resolved.

* Renamed add_task_traceback to add_protocol_dag_result_ref_traceback
* Added tests for add_protocol_dag_result_ref_traceback

Implemented half of the resolve_task_restarts test

With this decorator, if a transaction isn't passed as a keyword arg, one
is automatically created (and closed). This allows a chaining behavior
where many method calls share a single transaction object.

* Removed custom tokenization
* Implemented _defaults to allow default tokenization to work

cancel_map has been changed from a defaultdict to a base dict and
instead using the dict.get method to return None. Additionally added a
set of all task/taskhub pairs that is later used to determine what
should be canceled.

I've also added grouping on taskhubs so the number of calls to
cancel_tasks is minimized.

Also expanded test to check behavior of the task that was meant to be
waiting.

We don't want to change `_defaults()` from what's done in the base class
unless we have real default values to leave out of the hash.

…olicy_resolve_restarts

Restart policy: resolve restarts

The addition of source_keys and failure_keys was not included in the
unit tests so all initializations of Tracebacks failed. I've added
default values for the test class.

* add_task_restart_patterns
* remove_task_restart_patterns
* get_task_restart_patterns
* set_task_restart_patterns_max_retries

Additionally, I added the get_taskhubs method to Neo4jStore since
get_taskhub will only get the taskhub for a single network at a
time. It might make sense to replace the old method with this new one.