influxdb: improvements to influxdb query editor, SLIMIT, LIMIT and ORDER BY now added on demand by plus button

Decimals mapped to floats for now. No mapping for bit or
any of the blob types. Tinyint not mapped to bool.

In fact, the unit of `time_ms` int http logging is not "ms", this patch fix it.

The bug was happening because the background color was being based on
the rounded value (accounting the user defined decimals). Changed it to
use the pure value (not the rounded) to follow whats being done in the
value color, and also in the table thresholds (they don't consider the
decimals when comparing to thresholds).

Avg column was being added at every rendering, if the table was empty.
Now the column will be added once as an initialization when selecting a
'timeseries_aggregations' transform.

ref #3302

ref #7934 
ref #7968
ref #3164

ref #8277, ref #8250, ref #8262, ref #8165, ref #8093, ref #8056, ref #8043, ref #7970, ref #7914, ref #7864, ref #7750, ref #7740, ref #7697, ref #7619, ref #5619, ref #4030, ref #5278, ref #3302, ref #2524

fix: fixed slow down issue in table panel by removing the fillter null values feature (#7602), not sure the filter null values is a good table option, should be done in metric query, fixes #8234