Improve user-friendlines / readibility of catalog navigation

[jetschny]

From the user perspective it is not straight forward to get from
https://catalog.eoxhub.fairicube.eu/?.language=en
to the desired data set. first, we have 3 collections under the landing page, one of the collection is called "catalog" which is misleading. description of the collections can improve to clarify the seperation. maybe we can fake-call the collections "catalogs" as well as users might not know the meaning of the collections?

further, when going to the data access catalog

https://catalog.eoxhub.fairicube.eu/collections/index

a prominent free-text search field would be great (but not doable yet due to the querry restrictions from the stac browser). The issues / improvements in the search querry are covered in other GitHub issues.

When selecting a dataset the technical description is fine (right side of the screen) but the labeling of items on the left side (Assets, Additional resources) is not intuitive to understand. Where is the link to my data, where can I download? I understand that the terminology might come from Stac but we have to verify with users (UCs) how to label it properly so that users get from the landing page to the download link. another github isse covers the actual access [link/information] to the data. Suggestion is to go through together with the UCs and agree on labels / names once we know what we can actually change due to stac browser configuration restrictions.

[KathiSchleidt]

Clarification: as most elements are NOT correctly mapped to STAC, STAC is not the culprit here!

Related to #32 and the attempt by S4E to get better descriptive texts in the WebGUI (also failing due to lack of STAC alignment)