Session timeout controlled from Influxdb UI

__Use case:__
- Any monitoring user with admin rights needing to modify the session time. i.e. Dashboard user
- Working with Influx DB UI for longer than 1 hr at a time.
- non-coder requiring to modify the session time
- modifying config options without having to restart the Docker container

__Proposal:__
Influx DB UI to have GUI for modifying session length. The session is currently set at 60 minutes as default. However, for many use cases session needs to be longer or even be infinite.
It is difficult to modify configuration file for Influx DB especially if you are running containerised version of it.
Having a GUI within the UI would significantly lower the difficulty.

__Current behaviour:__
Need to modify the config file to adjust the session length.

__Desired behaviour:__
Can modify the session length from InfluxDB UI.

__Alternatives considered:__
- Entire config adjustable from the UI
- Infinite session length (for users using InfluxUI dashboard permanently

No implementation files or tests are named. Start by reading the README contributing section and locating the existing session-time configuration; done means an admin can change the timeout from the UI without restarting the container, with the requested longer or infinite-session behavior defined.

Written by the indexing model from the issue text.