Fix #20797: Added "No Matching Streams." when no result is found.

[cynthialiuu]

When users search for a stream that doesn't exist, 'No matching strea…ms.' will appear. This maintains consistency with the user search, which shows 'No matching users.' and improves the UI of the search feature.

Fixes: Show no search result message in filter stream search #20797

Tooling tips: https://zulip.readthedocs.io/en/latest/tutorials/screenshot-and-gif-software.html
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Screenshots and screen captures:

Self-review checklist

• Self-reviewed the changes for clarity and maintainability
  (variable names, code reuse, readability, etc.).

Communicate decisions, questions, and potential concerns.

• Explains differences from previous plans (e.g., issue description).
• Highlights technical choices and bugs encountered.
• Calls out remaining decisions and concerns.
• Automated tests verify logic where appropriate.

Individual commits are ready for review (see commit discipline).

• Each commit is a coherent idea.
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Completed manual review and testing of the following:

• Visual appearance of the changes.
• Responsiveness and internationalization.
• Strings and tooltips.
• End-to-end functionality of buttons, interactions and flows.
• Corner cases, error conditions, and easily imagined bugs.

[alya]

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[Faten-toujani]

code issue.pdf

this identified some style and dependency issues. what we need to correct is : resolving the CSS color function, running Prettier to fix formatting, and refactoring code to eliminate circular dependencies. :
1 - Problem: The code uses an outdated way to specify colors in CSS.
Solution:
Locate line 105, column 12 in : " web/styles/left_sidebar.css "
Identify the outdated color function (e.g., rgb(255, 0, 0)).
Replace it with a modern color function, such as:
Hexadecimal notation: #( the code of color )
You can refer to this website: https://www.rgbtohex.net/

2- ESLint - Import Order : "./stream_list " is imported after " ./user_settings, "but should be imported before.