Currently we have a `Util`-helper for computing the bounding-box of a Bézier curve, however for simple points and rectangles we repeat virtually identical code in many spots throughout the code-base.
- Introduce new `Util.pointBoundingBox` and `Util.rectBoundingBox` helpers.
- Remove the "fallback" from `Util.bezierBoundingBox` and only support passing in a `minMax`-array, since there's only a single call-site using the other format and it could be easily updated.
The current logic assumes that all spans in the text layer contain
only one text node, and thus that the position information
returned by `highlighter._convertMatches` can be directly used
on the element's only child.
This is not true in case of highlighted search results: they will be
injected in the DOM as `<span>` elements, causing the `<span>`s
in the text layer to have more than one child.
This patch fixes the problem by properly converting the (span, offset)
pair in a (textNode, offset) pair that points to the right text node.
Given that most inferred links will overlap existing LinkAnnotations, creating a lot of unused `borderStyle` objects seem unnecessary.
Hence we can move that into the `AnnotationLayer.prototype.addLinkAnnotations` method instead, which also allows us to slightly reduce the API-surface.
Automatically detect links in the text content of a file and automatically
generate link annotations at the appropriate locations to achieve
automatic link detection and hyperlinking.
