[$40] Fix total when fallback to DB in search requests

[maxceem]

At the moment if search requst fallbacks to DB, the total is calculated in a wrong way, it only returns the number of objects for the current page. While it has to return the number of objects in total for all the pages.

Previously we fixed this issue for GET /resourceBookings see https://github.com/topcoder-platform/taas-apis/blob/dev/src/services/ResourceBookingService.js#L649-L656

We have to fix search requests for other endpoints:

• GET /work-periods

• GET /work-period-payments

• GET /jobs

• GET /jobCandidates

• GET /jobCandidates/:jobCandidateId/interviews

• GET /taas-roles

• To make it easier to see from where we get data DB or ES, update function setResHeaders https://github.com/topcoder-platform/taas-apis/blob/dev/src/common/helper.js#L787-L813 to also set one more header X-Data-Source with values database or elasticsearch. Note, that we already pass flag result.fromDb to this method.

• Provide verifications screens that show that for each of these requests, the total returned from ES is the same when returned from DB.

• To test request from DB, the ES service could be stopped docker stop tc-taas-elasticsearch.

[xxcxy]

GET /taas-roles
This api does not support paging.

[maxceem]

GET /taas-roles
This api does not support paging.

I see, then no need to fix it for this endpoint.

[maxceem]

Paid via https://www.topcoder.com/challenges/883c8a2f-c411-49ca-b3e1-c9bea7c9d37a

[maxceem]

This is not possible to test via QA, but verification screenshots were provided in PR #341.

Closing.