Syntax highlighting breaks in multi-line attributes

[brunnerh]

Describe the bug
If an attribute value contains multiple lines and the first line has no interpolation, the syntax highlighting of interpolations in later lines will not be applied.

To Reproduce

Example component:

<script>
	export let question = 'Really';
	export let flag = true;
</script>

<!-- Second line highlighted. -->
<div title="{question}?
	{flag ? 'Yes' : 'No'}"/>

<!-- Second line not highlighted. -->
<div title="Really?
	{flag ? 'Yes' : 'No'}"/>

(The same seems to be true for the highlighting on GitHub.)

Expected behavior
Syntax highlighting on all interpolations.

Screenshots

System (please complete the following information):

• OS: Windows 10, 64bit
• IDE: VSCode 1.48.1
• Plugin/Package: Svelte for VSCode (v101.10.0)

[dummdidumm]

If this is fixed, the syntax highlighting part of #381 is probably fixed, too.