Relate more to `data.content` in the explorer

[perolavsvendsen]

The data.content tag is quite central, and is actively white-listed and standardized through fmu-dataio. However, the explorer does not relate much to it. It does, however, have some knowledge about the data.tagname property which can be problematic down the line.

• No standard on data.tagname, its main purpose is to provide unique filenames on the disk
• Each asset will have their personal customized way of setting "tagname", so no logic can be built on the tagname. A key purpose with the new data standard - and Sumo - is to enable scalable data consumption.
• If applications such as Webviz start using logic on data.tagname we are recreating the current problems, and even possibly making them worse.

[equinor-ruaj]

Refinement 30.10.2023:

• PR to fmu-dataio with Eclipse data types.
• Explorer examples in readme: check that they work and fix
• Verify: can Explorer filter on content?
• Explorer: add method for more "advanced" filtering. User specifies path to properties. (Something like ExcludeIf or Require/NotRequire?)
• Explorer: enable going from case -> content -> data. ContentCollection? (In the case where user wants to browse all data with a given content but does not care about data.type)