Explore: Remember last used datasource

Fixed issues with panel size in edit mode, fixes #14703

Update yarn.lock

Loki: query limit configurable in datasource

Logs data model: add more log levels

Tweak datetime picker layout for mobile

- use local storage to store last used database
- renamed `datasourceName` property to `initialDatasourceId` for consistency
- adapted tests

only update session in mysql database when required

fix only create/drop database indices if not exists/exists

- add `eror` used in github.com/inconshreveable/log15 (used by Grafana as well)
- add levels from SYSLOG

Loki: change query row to be single field again

Explore: logging UI style fixes

Explore: fix loading indicator z-index on panel container

- existing z-index placed the loading indicator above dropdowns of the panel children
- removed z-index for natural ordering

- tried split selector and search for a week, and it did not feel natural
- keeping some of the original modifications in QueryField from splitting PR
- adapted CheatSheet and placeholder text
- added new label selector state: No labels found

- baseline aligment for meta field labels
- use variables for font sizes and margins

- Loki queries must contain a limit
- this change makes this limit configurable in the datasource
- keep default at 1000, add tooltip on why inc/dec makes sense
- added tests

WIP: makes cache mode configurable

Adds orgId to user dto for provisioned dashboards

Closes the body properly on successful webhooks

this commit also adds a test docker container
for receiving alerting web hook requests

Fix general tab typos

this makes the cache mode in the sqlite connection
string configurable. the default also changed from
shared to private to solve #107272 but allow the user
to use shared if performance is more important.

ref #10727

Husky and sasslint fixes