[NONEVM-916] main LogPoller loop

[reductionista]

JIRA: NONEVM-916

This PR is intended to tie together the various pieces of LogPoller and implements the main run loop of LogPoller, responsible for processing and saving logs to the ORM. Minor adjustments to some of the pieces have been made to help them fit together better.
It will include the logic for backfills, borsch decoding and extraction of subkeys, as well as applying the actual filters to the stream of logs coming from the log ingester. And filling in the rest of the constructor, calling it, and specifying the LogPoller interface.

[cl-sonarqube-production]

Quality Gate failed

Failed conditions
0.0% Coverage on New Code (required ≥ 75%)
34.0% Duplication on New Code (required ≤ 5%)
C Reliability Rating on New Code (required ≥ A)

See analysis details on SonarQube

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[reductionista]

Split this JIRA in 2 and renamed them both. Closing this and re-opening it to rename the branch accordingly:
#1002