Clean up/organize examples

[perolavsvendsen]

We need to go through the examples, and restructure them a little bit.

• Examples intended for FMU users are mixed with notebooks not intended (or suited) for FMU end users.
• Some examples do not work/are outdated.
• It is not clear what the examples are examples of. Some examples are showing how you can use fmu-sumo while other examples seem more related to internal benchmarking
• All examples are defaulted to use dev - we don't want others to use the Sumo dev environment.

TODO

• Remove, or completely rewrite table example. It does not work.
• Update the main example notebook
• Move non-examples to another folder?

[equinor-ruaj]

Reopening: was only partly solved