feat: Allow switching the ImageManager driver

[imorland]

I recently identified an issue where image uploads were rendered with different color gamuts if they had been processed by Intervention in any way (resized, etc), if they had an embedded icc color profile. By switching to imagick, this profile was respected. Therefore, I'd like to introduce the option to use either driver everywhere in Flarum.

We use the ImageManager from Intervention in plently of places, both in core and extensions. Intervention supports two drivers - gd (default) and imagick. ref

This PR adds the possibility to switch to imagick, if this is required.

By default gd will still be used, however, adding the following to config.php, one can specify the alternative:

'intervention' =>
  array (
    'driver' => 'imagick',
  )

Extensions should update their code and refrain from new ImageManager() and resolve the singleton from the container instead.

Necessity

• Has the problem that is being solved here been clearly explained?
• If applicable, have various options for solving this problem been considered?
• For core PRs, does this need to be in core, or could it be in an extension?
• Are we willing to maintain this for years / potentially forever?

Confirmed

• Frontend changes: tested on a local Flarum installation.
• Backend changes: tests are green (run composer test).
• Core developer confirmed locally this works as intended.
• Tests have been added, or are not appropriate here.

Required changes:

• Related documentation PR: (Remove if irrelevant)
• Related core extension PRs: (Remove if irrelevant)

[matteocontrini]

Pay attention to the fact that ImageMagick by default not only doesn't strip the ICC profile but EXIF data in general, which means that GPS data contained in an image's EXIF could be unintentionally leaked to everyone.

[askvortsov1]

Could we inject the ImageManager as a constructor dependency where possible?

Pay attention to the fact that ImageMagick by default not only doesn't strip the ICC profile but EXIF data in general, which means that GPS data contained in an image's EXIF could be unintentionally leaked to everyone.

We'd still be using gd as the default though? I feel like this is something we might want to mention in documentation rather than adding a layer to address it ourselves.

[imorland]

I feel like this is something we might want to mention in documentation rather than adding a layer to address it ourselves.

Agreed. I'll look at adding something for this in fof/upload to protect GPS data, etc

[matteocontrini]

Agreed. I'll look at adding something for this in fof/upload to protect GPS data, etc

If it helps, this is what I've been doing in a private extension in production for years I think:

$exif = $img->getCore()->getImageProfiles('exif', false);
if (count($exif) > 0) {
    $img->getCore()->removeImageProfile('exif');
}

The exif profile includes for example the GPS data but not the ICC data.