Support Spock framework + some minor improvements and bugfixes

[yaronyam]

• Added an entry on TestMe popup UI to generate Spock test
• Better auto identification of matching test root directory in a multi module project without prompting the user
• Initialize tested subject class directly when no mocks generated
• Skip generation of mock supporting statements (imports, @Before..) when no mocks generated
• Skip generation of test subject initialization statement when only static methods being tested
• Improve constructor selection and initialization of non static nested classes

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