Update explorer

[Peter9192]

The explorer hosted at https://explore.ewatercycle.org/. When you select a "start experiment" you should get a notebook that uses the updated ewatercycle python package.

• Update the notebook template in https://github.com/eWaterCycle/experiment-launcher should be updated.
• Change the name of the notebook in https://github.com/eWaterCycle/terriajs and
• Change fetching the right datasets in https://github.com/eWaterCycle/TerriaMap
• Include wflow pcrglob and marrmot, and their example use cases.

[sverhoeven]

See PRs

• https://github.com/eWaterCycle/experiment-launcher/pull/29
• https://github.com/eWaterCycle/terriajs/pull/10
• https://github.com/eWaterCycle/TerriaMap/pull/6