Summary:
On Firefox and Safari, setting scrollLeft to a max safe integer was
causing it to be treated as 0. It's not clear why - for now, the
scrollWidth is used instead.
Also fixes a bug where the column title popup wouldn't appear for a
new column if tab was previously used to close the same popup for
the last column.
Test Plan: Browser test.
Reviewers: JakubSerafin
Reviewed By: JakubSerafin
Subscribers: dsagal
Differential Revision: https://phab.getgrist.com/D3911
0b64e408b0