Mattermost-server: Show search tip when scrolling back a lot in a channel

[mattermod]

Summary: Inform users of the search shortcut when the user has scrolled 3 times his window height back into a channel. Note that this ticket is blocked on implementing this change to search shortcuts: https://github.com/mattermost/mattermost-server/issues/15639

The shortcut that is displayed should work and would be displayed as follows:
Web app (Browser)
Cmd+Shift+F for Mac
Ctrl+Shift+F for Windows

Desktop App
Cmd+F for Mac
Ctrl+F for Windows
Using those shortcuts would take your focus to our in app search bar, and popular the search bar with the “:in” identifier and the current channel.
So in the case of the screenshot, it would be: in:design-high-impact-uiux

Note: do not show this banner in mobile web view responsive mode

See related ticket that adds the in: modifier to the search field when the CTRL/CMD + F is used from a channel: https://mattermost.atlassian.net/browse/MM-19327

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JIRA: https://mattermost.atlassian.net/browse/MM-27913

[TheDarkestDay]

Can I take this one instead of https://github.com/mattermost/mattermost-server/issues/15214 ?

Do you have any Figma designs for this tooltip?

[esethna]

@TheDarkestDay yes figma designs are here: https://www.figma.com/file/FBBQQs6WiboS8shpMwVo2l/MM-27913-Search-Tip-Center-Channel?node-id=166%3A2817

[TheDarkestDay]

@TheDarkestDay yes figma designs are here: https://www.figma.com/file/FBBQQs6WiboS8shpMwVo2l/MM-27913-Search-Tip-Center-Channel?node-id=166%3A2817

Unfortunately, this link says that either I have no access to this file or there is no such file at all. Should I go through some procedure in order to get access?

[TheDarkestDay]

How this "hint" should actually interact with all of the existing channel list floating toasts, like the one for unread messages? Should it float above them or should it reside somewhere below?

[esethna]

@TheDarkestDay try again now! https://www.figma.com/file/FBBQQs6WiboS8shpMwVo2l/MM-27913-Search-Tip-Center-Channel?node-id=166%3A2817

Good question, I would say that the unread channel toast and this search tip should never exist at the same time, the unread toast should always prevail

[TheDarkestDay]

Feel free to check my PR - https://github.com/mattermost/mattermost-webapp/pull/6896