CP-17510 image cursor

[niden]

Hello!

• Type: bug fix
• Link to issue: [BUG]: Image\Adapter\Imagick::processReflection() advances the wrong frame cursor #17510

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• I have read and understood the Contributing Guidelines
• I have checked that another pull request for this purpose does not exist
• I wrote some tests for this PR
• I have updated the relevant CHANGELOG
• I have created a PR for the documentation about this change

Fixed Phalcon\Image\Adapter\Imagick::processReflection() applying the reflection to the first frame only of a multi-frame image, because the first two loops changed the reflection clone but moved the frame cursor of this->image

Fixed Phalcon\Image\Adapter\Imagick::background(), reflection(), text() and watermark() discarding any opacity below 100, and sharpen() rounding its amount down, because the division by 100 was stored back in the integer parameter; watermark() left the image unchanged for every opacity except 100

Fixed Phalcon\Image\Adapter\Imagick never coalescing the frames of a GIF, because the constructor compared getImageType(), an Imagick IMGTYPE_* value, against IMAGETYPE_GIF; the width and the height of an animated GIF now describe the canvas instead of whichever sub frame the cursor was on

Fixed Phalcon\Image\Adapter\Imagick::render() returning the current frame alone for a GIF, and save() failing with no encode delegate for this image format after an operation that rebuilds the image; both now mark every frame with the format, which setImageFormat() applies to the current frame only

Thanks