Yearly rrule compliance by the iterator

[kroky]

Make the RRuleIterator always follow the yearly RRULE even when start date does not follow the rule. Should solve https://github.com/sabre-io/vobject/issues/626

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 98.78%. Comparing base (8bf65e2) to head (72a1fe9). Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##             master     #656   +/-   ##
=========================================
  Coverage     98.78%   98.78%           
- Complexity     1868     1869    +1     
=========================================
  Files            71       71           
  Lines          5253     5254    +1     
=========================================
+ Hits           5189     5190    +1     
  Misses           64       64           

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[phil-davis]

I added a couple more test scenarios just to cover when the specified start date is in a month before/the same as/after the month where the recurring event should happen. It passes.