Influxdb: Deprecate database field and move to jsonData

[gtk-grafana]

Following the plan laid out in #59098, and mentioned in #58647 (comment), we should migrate the database field into the jsonData, as the database field is deprecated in #58647.

Need to maintain backwards compatibility for initial release, and create a plan for eventual complete deprecation of the old field.

[gtk-grafana]

@gabor What is the impact of releasing/not releasing this?

[gabor]

@gtk-grafana i don't think there is any short-term impact.

the current behavior of (influxdb&elastic) has been deprecated. it will work fine until grafana-core completely removes support for this. i mean, until they remove these lines: https://github.com/grafana/grafana/blob/main/pkg/api/frontendsettings.go#L323-L324

whether that will be ever removed, i don't know, my guess is that it won't be removed for some time, maybe @marefr has a better estimate.

still, i think it's a good idea to start migrating users to the "better" approach (i mean, doing the step1 from #59098).

i hope this explains the question, if not, ping me :)