fix(prefer-separate-static-class): ignore .attr and .prop class bindings - #3219

vue/prefer-separate-static-class reports :class.attr="'emoji-trigger'" and :class.prop="'hint'" like a plain :class, and --fix turns them into class="...", which changes what renders. Vue compiles these modifiers into ^class and .class keys (vBind.ts), so the value skips class normalization and fallthrough merging, and runtime-dom writes it as a raw attribute or as the class DOM property instead of calling patchClass (patchProp.ts). Moving such a value into a static class attribute isn't an equivalent rewrite. Playground: all three lines are reported on 10.12.0, only the plain :class one should be.

The rule now skips v-bind:class with .attr or .prop, including the .class shorthand. .camel is still reported, since it leaves class unchanged.

Fixes #2534