Add Clover tab for Build Summary page

Problem:

Currently Clover tab is displayed on:

• Plan Summary - yes
• Build Summary - no
• Job Summary - yes

It's misleading for end-users that they see stats on Plan Summary and have the link to Clover report from the BUILD, but when they go to the Build Summary they don't see Clover tab.

Suggested improvement:

1. Add Clover tab on the Build Summary page if:

• there is at least one Job with Clover configured (manual or automatic integration) and
• there is at least one "Clover Report" artifact or clover.xml file available

2. What to display on this Clover tab (in the following priority):

• if there is exactly one "Clover Report" artifact in some Job (and there are no clover.xml files in other Jobs) -> display Clover Report (HTML) exactly as it's presented on a Job Summary page;
• otherwise if there is exactly one clover.xml file in some Job -> display Clover Statistics (XML) exactly as it's presented on a Job Summary page
• otherwise display a message like "Several Clover reports found. Choose: " and a list of "Job name + hyperlink to Job Summary / Clover tab"

Out of scope:

Merging of Clover databases from multiple jobs and generating of single consolidated report.