fix so that google analytics script are cached

prometheus: variable query should fallback correctly to a series query 

sql tsdb: fix value columns conversion to float when using timeseries query

fix misalignment of unit and other drop downs in firefox

removed height 100% from panel-container to fix ie11 panel edit mode

Add weback-dev-server with hot/hmr support

Using a query of for example up or up{job=job1}

Add silent option to backend requests

Added requests/sec(throughput)

allow to show more preview values for variables

Fixes #11707

fixed so user who can edit dashboard can edit row

Fix ineffassign issues

From review feedback:

* s/helper/metadata
* combined positional args to _request into options dict
* metadataRequest reuses _request()
* moved consumption of this.httpMethod into _request, can be overwritten
 in options due to spread-after

* loadStore() modified the url which triggered a new render path, this
gets noticed by react. Moved to componentDidMount.