fix(compiler-ssr): fix SSR issue when dynamic and static class used

[mathieutu]

Hi,

First PR on Vue3, and first time looking at the SSR process!
This one kept me busy few hours, to understand how all of that that runs (hurray for the debugger!).

As you can see in the Template explorer, there is an issue with the ssr compiler.

In the case of a dynamic class attribute first, we end up with:

// input
<div :class="'dynamic'" class="child"></div>

// render function
<div${
    _ssrRenderClass(['dynamic', "child"])
  }" class="child"></div>

// output
<divdynamic child" class="child"></div>

Instead of, if we invert the order:

// input
<div class="child" :class="'dynamic'"></div>

// render function
<div class="${
    _ssrRenderClass(['dynamic', "child"])
  }"></div>

// output
<div class="dynamic child"></div>

(Actually, it happens only if there is a parent, but I've omitted it in the example, for simplicity)

This comes from the removeStaticBinding function in compiler-ssr/src/transforms/ssrTransformElement.ts which is supposed to remove the static binding, but which in fact removes only the first one found.

This PR adds some tests to reproduce the bug and fixes the issue.

Thanks for your work!

Matt'

[mathieutu]

The failing tests are about suspense and seem to be totally out of the scope of this PR.

[yyx990803]

Great job hunting this down!