fix(useElementSize): fix incorrect element size on SVG

[Lionad-Morotar]

Description

fix #2084

fix incorrect size on SVG element, due to https://www.w3.org/TR/resize-observer/#calculate-box-size

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.
• 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.

[wheatjs]

Looks good to me unless anyone thinks this will introduce some breaking changes, but I can't see any obvious ones.

[Lionad-Morotar]

vueuse/packages/core/useElementSize/index.ts

Line 27 in da0d726

const isSVG = computed(() => unrefElement(target)?.namespaceURI?.includes('svg'))

Method isSVG check only svg tag. What about the g tag?
Ex: I am building inside svg -> d chart and want to center align using translate (svg width 100%)

It seems works fine with "g" tag:

g、path 等标签也支持。不过，我觉得 getComputedStyle 这个方法也许换成 getBoundingRect 会更好一些？

[MstrVLT]

getComputedStyle

that was the problem - thx!