ref #7541

Changes default from name in smtp settings
from Grafana Admin to Grafana.

Fix for integration test (which is skipped but that
did not work)

Updates mailer to include `from_name` value

Updates the messafe `From` field to include the name and email of the
sender.

Updates the `SmtpSettings` struct to include a value for setting the
name of the email sender.

Add more physics units

Closes #7449

annotation: wrap text in drop_element, fixes #7542

update datasource logos

this will save us ~100TB of unneeded data in the long term.

Currently there is a limit of 1000 users in the global
user list. This change introduces paging so that an
admin can see all users and not just the first 1000.

Adds a new route to the api - /api/users/search that
returns a list of users and a total count. It takes
two parameters perpage and page that enable paging.

Fixes #7469

(feat) support datasource delete by name api