[Bug] Incorrect years range is displayed in the viewMode header

[Sabarish-Vasudevan]

Fixed the incorrect range that is displayed in the year navigation header.

Description

• Fixed year navigation.
• Modified Test cases for yearly navigation

Motivation and Context

• Why do you think this pull request should be merged?
  • This PR should be merged because when the date picker is in the years picker view, the range of years is displayed incorrectly.
• Does it solve a problem, in that case what problem?
  • Yes it does solve a problem as mentioned above. Refer image for more clarity.

In the above image, the range should be 2019 - 2030, but it is shown as 2020-2029

• If these changes fixes an open issue, please provide a link to the issue here
  • Yes. Issue

Checklist

[x] I have not included any built dist files (us maintainers do that prior to a new release)
[x] I have added tests covering my changes
[x] All new and existing tests pass
[ ] My changes required the documentation to be updated
[ ] I have updated the documentation accordingly
[ ] I have updated the TypeScript 1.8 type definitions accordingly
[ ] I have updated the TypeScript 2.0+ type definitions accordingly

[Sabarish-Vasudevan]

@arqex Could you please review this PR?