search_box: Improved search box query handler.

[aryanshridhar]

Earlier , The query typed in search box is erased when the user navigates to a new stream . As suggested by @neiljp here , Added a extra keybinding of meta /( alt /) which retains the search query and carries it forward whenever the user changes narrows .

It includes :

• If the user wants to perform a non-sticky search across narrows , the usual keybinding of / would make the job done .
• But , if user prefers for a sticky-search , activating the searchbox with meta / is useful.

Non-Sticky Search : (/)

Sticky Search :(meta /)

Would love an review @neiljp .

[neiljp]

@aryanshridhar Do you intend to continue this soon? I don't believe we have an issue for this?

[zulipbot]

Heads up @aryanshridhar, we just merged some commits that conflict with the changes your made in this pull request! You can review this repository's recent commits to see where the conflicts occur. Please rebase your feature branch against the upstream/main branch and resolve your pull request's merge conflicts accordingly.