#1825 Add Progress Bar mode to TimerLab

[ChesterSng]

Fixes #1825
Outline of Solution

The progress bar is implemented the following way:

1. Create two bars (each of same height and width of the timer body)
2. First bar is filled with colour, second bar is transparent.
3. Concatenate second bar to first bar and group the two bars
4. Align first bar with the timer body.
5. Apply Shrink to 0 width animation to the progress bar over set duration.

Functional Tests are added for Progress Bar:

1. Tests on the original timer lab are tested again when progress bar is enabled
2. Added test case when there is already a timer on the slide and progress bar is enabled/disabled

• Implementation of Progress Bar
• Adding Functional Test Cases for Progress Bar
• Refactor Code

[blewjy]

Hey @ChesterSng, great job with this new feature! I think it's a cool feature and a very ingenious way of using the grow/shrink animation here. Working perfectly on PPT2013, including updated FT.

I only have some comments on the code, other than that, LGTM!

[YuPeiHenry]

Tested and working on PowerPoint 2010. Please extract the reused block of code into a separate function.