ENT-3674: Change PAYG tally output to running total format

[kahowell]

This introduces into the TallyResource the concept of "running total format". Running total format is currently enabled when the product ID supports hourly granularity.

Running total format does two things:

1. It transforms tally snapshot data by making it additive (snapshot for a given date is the sum of previous dates in the response.
2. It alters the filler to use previous snapshots for generating snapshots (rather than 0-valued snapshots).

Another related change I made was if we are producing a default snapshot for a given timestamp in the future, the values are set to null. This should cause the graph to omit the data point (making the dropoff abrupt at the edge of data).

Testing Suggestions

Deploy via RBAC_USE_STUB=true ./gradlew bootRun

Truncate existing tally data and insert some new:

truncate table tally_snapshots cascade;
INSERT INTO tally_snapshots (id, product_id, account_number, granularity, snapshot_date, sla, usage) VALUES ('1718a2fd-12eb-4c51-a7f1-7774bce33bfd', 'OpenShift-dedicated-metrics', 'account123', 'DAILY', '2021-04-01', '_ANY', '_ANY');
INSERT INTO tally_measurements (snapshot_id, measurement_type, uom, value) VALUES ('1718a2fd-12eb-4c51-a7f1-7774bce33bfd', 'TOTAL', 'CORES', 2);
INSERT INTO tally_snapshots (id, product_id, account_number, granularity, snapshot_date, sla, usage) VALUES ('dbb8e7c7-84da-4e80-a512-85e6a560b833', 'OpenShift-dedicated-metrics', 'account123', 'DAILY', '2021-04-02', '_ANY', '_ANY');
INSERT INTO tally_measurements (snapshot_id, measurement_type, uom, value) VALUES ('dbb8e7c7-84da-4e80-a512-85e6a560b833', 'TOTAL', 'CORES', 4);
INSERT INTO tally_snapshots (id, product_id, account_number, granularity, snapshot_date, sla, usage) VALUES ('96e8f3cb-8f71-4b3e-98cf-94c170e59e51', 'OpenShift-dedicated-metrics', 'account123', 'DAILY', '2021-04-08', '_ANY', '_ANY');
INSERT INTO tally_measurements (snapshot_id, measurement_type, uom, value) VALUES ('96e8f3cb-8f71-4b3e-98cf-94c170e59e51', 'TOTAL', 'CORES', 16);

Next, hit the endpoint for April 2021, and see the resulting snapshot values (esp. notice that future dates have null to visually indicate there is definitely no data for them yet):

curl -X 'GET' \
  'http://localhost:8080/api/rhsm-subscriptions/v1/tally/products/OpenShift-dedicated-metrics?granularity=Daily&beginning=2021-04-01T00%3A00%3A00Z&ending=2021-04-30T23%3A59%3A59.999Z' \
  -H 'accept: application/vnd.api+json' \
  -H 'x-rh-identity: eyJpZGVudGl0eSI6eyJhY2NvdW50X251bWJlciI6ImFjY291bnQxMjMiLCJ0eXBlIjoiVXNlciIsInVzZXIiOnsiaXNfb3JnX2FkbWluIjp0cnVlfSwiaW50ZXJuYWwiOnsib3JnX2lkIjoib3JnMTIzIn19fQo='

(can also use swagger-ui at http://localhost:8080/api-docs)

[kahowell]

Reviewer, please don't merge until @cdcabrera confirms that output such as

{
  "date": "2021-04-21T00:00:00Z",
  "has_data": false,
  "has_cloudigrade_data": false,
  "has_cloudigrade_mismatch": false
}

won't cause issues for the GUI. @cdcabrera, please leave any feedback here.

[lindseyburnett]

What do you think of making overloaded fillWithRange, so there's not this "magic number null" parameter when reading through this logic? Something like fillWithRange(date,date,offset) which will pass "null" and "false" as the last two parameters of fillWithRange(date, date, offset, lastSnap, useRunningTotalFormat)

[lindseyburnett]

Random question, why do we always pull the ApplicationClock in for this instead of just doing Calendar.getInstance().getTime()?

[cdcabrera]

For the most part the GUI will compensate for any missing fields, if it knows about them, via our internal schema check. That applies towards the graph, graph tooltips, and any potential inventory alterations.

Currently, if the graph is missing a field, and it knows about it, the fallback is to mark that field undefined and assign it a 0 value. The GUI doesn't compensate for missing dates, if the dates are missing, the graph skips them.

This update does expose a bug'ish on the GUI that we aren't compensating for the field core_hours so we'll be pushing a Jira issue (ENT-3809) and update to coordinate with this update, otherwise the GUI appears to render like

Once the GUI corrects its schema check the display should look like

@mirekdlugosz
@ntkathole