fix(plugin-vue): trim template indent

[btea]

Description

fix #7594

Additional context

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

[patak-dev]

Are sourcemaps affected?

[Shinigami92]

So do I understand correctly that this will just remove the spaces and tabs from start and end of whatever in template is?

So yes, I would like to ask what @patak-dev asked

plus

Do we maybe just want trimLeft()?
And would that transform pug from

<template lang="pug">
◦◦div
◦◦◦◦.nested-div-1
◦◦◦◦◦◦.nested-div-1-1
◦◦◦◦.nested-div-2
</template>

to

<template lang="pug">
div
◦◦◦◦.nested-div-1
◦◦◦◦◦◦.nested-div-1-1
◦◦◦◦.nested-div-2
</template>

or even worse

<template lang="pug">div
◦◦◦◦.nested-div-1
◦◦◦◦◦◦.nested-div-1-1
◦◦◦◦.nested-div-2</template>

?
So that might produce 1. horrible source-map code, 2. invalid pug?

[btea]

I found that it also reported an error when build. Maybe should wait for compiler-sfc to fix this? see vuejs/core#3842

[patak-dev]

Yes, this should be fixed in compiler-sfc. Thanks for the PR and the link