Tab contents are transitioning in the wrong direction in RTL layout

[dvdchr]

Describe the bug
In RTL layout, tabs are lined up correctly but the contents still transition from left to right.

This is related to #4444; Upon investigation, we are using XLPagerTabStrip for our tab components. Unfortunately, the library forces the contents (i.e. view controllers) to be lined up in LTR layout regardless of the layout setting.

Note that this affects Stats and Orders.

To Reproduce
Steps to reproduce the behavior:

1. Change your sim or device to RTL (or use a pseudo-RTL language).
2. Go to Stats or Orders section.
3. Choose a different tab, and observe that the tab content transitions in LTR.

Screenshots

122379627-3a48f700-cf91-11eb-9b5b-1785fea622e1.mov

Expected behavior
I'm not used to RTL layouts, but I think the correct behavior here is to transition to the left – basically following the order of the tabs. Feel free to correct me if I got this wrong! 😄

Isolating the problem (mark completed items with an [x]):

• I have deactivated other plugins and confirmed this bug occurs when only WooCommerce plugin is active.
• This bug happens with a default WordPress theme active, or Storefront.
• I can reproduce this bug consistently using the steps above.

Mobile Environment
Please include:

• Device: iPhone 11
• iOS version: 14.5
• WooCommerce iOS version: 7.0

[dvdchr]

Some ideas:

1. Easiest workaround is to detect if we're in RTL layout (+ also listen to trait collection changes for directionality). If we're in RTL, then reverse the view controllers' array and forcefully scroll to the last element without animation.
2. Ideally, we should fork / submit a PR to fix this directly in XLPagerTabStrip. Because if/when the library fixed this issue, it would then mess up with the hack above.
3. Finally, we don't use a lot of features / styles offered by XLPagerTabStrip. Since the component is considerably simple, we could instead make our homegrown tab strip with proper RTL support.

[pmusolino]

We should verify if this is still an issue with the new home screen, planned to be released in 8.5.