Accept transform-origin inside @position-try

[Zhang-Junzhi]

When implementing a pop-over with anchor positioning, a common pattern is to animate its appearance using transforms (e.g., scaling or rotating). In such cases, it’s often desirable to set the transform origin at the vertex closest to the anchor point. Example:

.some-popover-ele
{
    display: none;
    opacity: 0;
    transform: scale(.97);
    transition: transform .2s, opacity .2s, display .2s allow-discrete, overlay .2s allow-discrete;
    position: absolute;
    top: calc(anchor(bottom) + 5px);
    left: anchor(left);
    transform-origin: top left;
    position-try: --popover-from-top-left, --popover-from-bottom-right, --popover-from-top-right;
}

.some-popover-ele:popover-open
{
    display: block;
    opacity: 1;
    transform: none;
    @starting-style
    {
        opacity: 0;
        transform: scale(.97);
    }
}

@position-try --popover-from-top-left
{
    top: auto;
    bottom: calc(anchor(top) + 5px);
    transform-origin: bottom left;
}

@position-try --popover-from-bottom-right
{
    left: auto;
    right: anchor(right);
    transform-origin: top right;
}

@position-try --popover-from-top-right
{
    left: auto;
    right: anchor(right);
    top: auto;
    bottom: calc(anchor(top) + 5px);
    transform-origin: bottom right;
}

Unfortunately, transform-origin is currently not allowed within @position-try. Therefore, I propose adding support for transform-origin in this context.