Summary:
User can freeze any number of columns, which will not move when a user scrolls grid horizontally.
Main use cases:
- Frozen columns don't move when a user scrolls horizontally
- The number of frozen columns is automatically persisted
- Readonly viewers see frozen columns and can modify them - but the change is not persisted
- On a small screen - frozen columns still moves to the left when scrolled, to reveal at least one column
- There is a single menu option - Toggle freeze - which offers the best action considering selected columns
- When a user clicks a single column - action to freeze/unfreeze is always there
- When a user clicks multiple columns - action is offered only where it makes sens (columns are near the frozen border)
Test Plan: Browser tests
Reviewers: dsagal, paulfitz
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2852
bdd4d3c46e