Fix occasional integration test failure and some IE issues

[andy-lee-eng]

IE uses left/right instead of x/y and different format "transform".
Use "closest" (with polyfill) to navigate up to the chart element.
Polyfill "matches" which is used by d3fc
Move default theme variables to where they actually need to be (IE/Edge don't get the variables otherwise)

[Ro4052]

What was causing the test failures?

[andy-lee-eng]

The get-root-container code was for some reason returning the plot-area instead of the custom element (which has the "getContainer" method).
I can only guess this is some weird artifact of the test context.
As the code that uses it was actually just trying to get the ancestor element, it seemed like "closest" was a better fit anyway.
But that isn't supported by IE without a polyfill, and in the process of checking that out, I found a whole load of other things broken in IE/Edge!

[matt-hooper]

@DevAndyLee
Did you have to do anything to your environment to get this to work?
I have pulled the new branch down.
Rebuilt all the packages and tried to run the tests, but all the puppeteer ones give me an error:

filter by a single instrument.: Failed to load resource: the server responded with a status of 404 (Not Found)

filter by a single instrument.: Failed to load resource: the server responded with a status of 404 (Not Found)

FAIL test/js/integration/candlestick.spec.js (5.644s)
candlestick.html
✕ filter by a single instrument. (2506ms)
✕ filter to date range. (586ms)

● candlestick.html › filter by a single instrument.

expect(received).toEqual(expected)

Difference:

- Expected
+ Received

- Array []
+ Array [
+   "Failed to load resource: the server responded with a status of 404 (Not Found)",
+   "Failed to load resource: the server responded with a status of 404 (Not Found)",
+ ]

  at Object.test (../../node_modules/@jpmorganchase/perspective-viewer/test/js/utils.js:295:32)

[matt-hooper]

I have done a completely fresh install and the tests now pass. I am not sure what was going with the 404 errors.