Accordion state

This is a PR adressing issues in #735 and reflecting discussion we had. It contains the following changes to the accordion:

- LayerManager: On desktop is always open on application start. There is a specific message when there are no layers selected yet. (This will need translation). On mobile, it is always closed on application start.

- Catalog: On desktop, the state of this accordion is determined by the topic.showCatalog parameter on application start and topic change, thus defined by our services. This requires https://github.com/geoadmin/mf-chsdi3/pull/186 to be merged and deployed. If this parameter is missing, the 'true' is assumed. On mobile, it is always closed on application start or topic change.

Note that both points do _not_ depend on or introduce new permalink parameter(s).