fix: Application page "permission denied" when navigating between applications in different namespaces

[Sir-Jacques]

This PR contains a proposed bugfix for a navigation bug which happens when navigating through the application-searchbar on top of the application-details page. When navigating to an application that is in another namespace on the kubernetes cluster, it will use the wrong url (/applications/xxxx instead of /applications/namespace/xxxx). With the fix to the ApplicationsDetailsAppDropdown, it navigates to the correct browser URL. Although the URL is correct it only loads the page after physically refreshing due to the next observation I came across.

In addition to the browser URLs being incorrectly constructed, I found that when navigating, the ApplicationDetails constructor does NOT run before the render function starts building the ObservableQuery. This means it keeps using the this.appNamespace from the previous page (it is not getting updated) to retrieve the application data. I'm very new to React so I have not been able to find out why. A workaround for this was to use the this.props.match.params.name directly instead of relying on the constructor to update the this.appNamespace. There must be a nicer way to do this? Any suggestions are welcome!

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Fixes #17781

[woehrl01]

Thank you @Sir-Jacques for that fix! I pushed a PR to your branch to also fix the UI part so that the namespace is shown as well in the search and some other fixes around that. See Sir-Jacques#1 this fixes #17781 completely for us.