Improve apps "About" page

Our apps have, all of them, an about page. Most of them are:
* Ugly
* Incomplete
* Incoherent (not the same approach if you compare apps)
* Unclear about the trademark

This concerns:
* Kiwix Apple
* Kiwix Desktop
* Kiwix Android
* Kiwix JS
* Kiwix Server

This issue is about creatin a common approach to improve them.

A good about should:
* Give the name of the app, the version, the license
* Give links (at least one) to the software project (on GitHub to give easy and clear access to changelog, releases, authors, bug reports).
* Explaining purpose of the software in a few sentences (maximum)
* Explaining the vision of Kiwix in a few sentences (maximum)
* Push the visual(s) of Kiwix (app): at least with the logo
* List all our dependencies (with license and link to the original project)

We should take in account our branded apps (see https://github.com/kiwix/overview/issues/139 and have a strategy to propose a slighly different version in there case). While extend this part later.

We should have a template design for these page. Once made, we will implement it in each app.

This issue does not tackle the very similar, but different, challenge of the about for scrapers.

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Nothing on Kiwix Server

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On iPadOS (and very same on iOS and macOS):

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Kiwix Desktop (Windows and Linux)

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Kiwix JS can be seen directly online at https://browser-extension.kiwix.org/current/www/index.html?contentInjectionMode=serviceworker&allowInternetAccess=true&referrerExtensionURL=moz-extension%3A%2F%2Fb3b44654-360e-4965-8639-80711f51a8c2&appTheme=light&showUIAnimations=false#modes

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Kiwix Android