fix: dont use thumbnails for emoticons

[marekvospel]

In this pull request I went over places where MxcImage is used and in case of custom emojis set isThumbnail to false, as the thumbnail generation causes emoticons to lose transparency and in some cases overall animations. (more info in #1071)

The only place I'm worried about is html_message.dart, where I'm using the following snippet: isThumbnail: (actualWidth * actualHeight) > (256 * 256). Maybe using something the data-mx-emoticon property would be more fitting?

Fixes #1071

• Code formatting and import sorting has been done with dart format lib/ test/ and dart run import_sorter:main --no-comments
• The commit message uses the format of Conventional Commits
• The commit message describes what has been changed, why it has been changed and how it has been changed
• Every new feature or change of the design/GUI is linked to an approved design proposal in an issue
• Every new feature in the app or the build system has a strategy how this will be tested and maintained from now on for every release, e.g. a volunteer who takes over maintainership

Pull Request has been tested on:

• Android
• iOS
• Browser (Chromium based)
• Browser (Firefox based)
• Browser (WebKit based)
• Desktop Linux
• Desktop Windows
• Desktop macOS

[krille-chan]

@marekvospel looks good to me :) thank you very much for your contribution. It looks like your commit is not correctly signed yet. Can you sign your commit? According to the policy only signed commits can go into the main branch. More info on that you can find here: https://docs.github.com/en/authentication/managing-commit-signature-verification/signing-commits

[marekvospel]

@marekvospel looks good to me :) thank you very much for your contribution. It looks like your commit is not correctly signed yet. Can you sign your commit? According to the policy only signed commits can go into the main branch. More info on that you can find here: https://docs.github.com/en/authentication/managing-commit-signature-verification/signing-commits

Will do, I just forgot the -S flag. 😅

[krille-chan]

Great! Thank you so much <3