OpenPaaS-Suite/esn-frontend-inbox#34: Added usage of the `esn-app-grid` web component

[itswillta]

Partially resolves OpenPaaS-Suite/esn-frontend-inbox#34. Please also refer to this PR for the actual code of the web component: https://github.com/OpenPaaS-Suite/esn-frontend-application-grid/pull/1

Note that we should also delete the code in our SPAs that use applicationMenuTemplateBuilder since it is not needed anymore with the introduction of the WC.

• Here's the desktop version of it:

• Here's the mobile version of it:

TODOs:

• [ ] Test this on Safari & Edge (<19)