fix(header): support collapsible header with multiple toolbars

[liamdebeasi]

Dev build 5.0.0-dev.201911141743.24e780d

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

1. IO and scroll listener did not work properly with multiple toolbars
2. iOS transition did not account for multiple toolbars when determining animation translate

What is the new behavior?

• Added a forEach to the header to toggle all toolbars, not just the first toolbar
• Adjusted iOS transition to account for the real title/back button top offsets when setting positioning of the fake title/back buttons.

Does this introduce a breaking change?

• Yes
• No

Other information