Explore: fix metric selector for additional rows

Handle suggestions for alternate syntax aggregation contexts

[skip ci]

Fix bug with background color in table cell with link

Datasource proxy cache refactor

alerting: adds tests for the median reducer

add minimal permission to docs

adds a test that verify that null values are not used
when calculating the median value in alerting

closes #10056

Gitlab -> GitLab

typo fix for "has"

alerting: increase default duration for queries

Related: #13690

In aggregation contexts using the alternate syntax form, labels will
precede metrics. A cursor at the label position cannot provide
meaningful suggestions unless a metric is specified. In the latter case,
no suggestions are presented at all.

Related: #13690

Add [hash] to grafana.{light,dark}.css

we should promote using longer queries since this should
increase the quality of the alerts. only using a 5min range
means that we will only have 4 datapoints in data is written
every min which is not good enough for the generic alert rule

Fix minor JSON typo in HTTP API docs

Updated login page logo & wordmark and responsive behavior

[skip ci]

Add delta window function to postgres query builder

- race condition in language provider leads to only one row getting
  selector options
- fixed by always returning the start task promise