InfluxDB 2.x, Annotations. Fix: send tags not as fields.

[Amerousful]

Old: events title="Sitespeed.io",text="${message}",tags=${influxDBTags} ${timestamp} New:annotations,${influxDBTags} text="${message}" ${timestamp}

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Fixes:

1. Send annotations as a tags, because the current logic sends them as fields.
2. Represent tags with keys, in format key1=value1,key2=value2, instead of value1,value2.
3. Rename events to annotations for appropriate naming. However, it might not be a good idea to change it because it would be inconsistent with the underlying logic in others "senders".