Improve "New policy" title

Problem

Currently no matter which policy user create, we will show the same title in editing page: **New Policy**, it would be a better experience if we added the policy type, so that it is more clear which policy type is being created.

Implementation

• frontend update title computed property to use titles based on policy type
• frontend update titles to include title for pipeline execution policies
• frontend update editTitles to include title for pipeline execution policies