Updates changed method names and fixes spec failures

Suggests to use a JSON structured log instead

Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/54102

Use the shared method in Ci::Pipeline

Currently, we do not cap amount of tests returned to frontend,
thus in some extreme cases we can see a MBs of data stored in Redis.

This adds an upper limit of 100 tests per-suite.

We will continue showing the total counters correctly,
but we will limit amount of tests that will be presented.

This commit reverts the previously introduced concurrent pipeline
schedule creation which was a viable solution for mitigating
inconsistent pipeline schedule by Sidekiq Memory Killer.

Fixing the bug

Currently, pipeline schedule worker is unstable because it's
sometimes killed by excessive memory consumption.
In order to improve the performance, we add the following fixes:

1. next_run_at is always real_next_run, which means the value
   always takes into account of worker's cron schedule
1. Remove exlusive lock. This is already covered by real_next_run
   change.
1. Use RunPipelineScheduleWorker for avoiding memory killer.
   Memory consumption is spread to the multiple sidekiq worker.