As a user I should be able to click on links in chart descriptions and open it in external browser

[adietish]

follows up on #590

Steps:

1. ASSERT: have a cluster that you're logged into
2. EXEC: in the context menu to the cluster node (in the resource tree), pick "Open Helm Charts"
3. EXEC: in the upcoming dialog, choose a chart that has a link in the description
4. EXEC: try to click onto the link

Result: Nothing happens

Expected result: The link should be opened in an external browser.