feat(useArrayReduce): new function

[yjl9903]

Description

Reactively array reduce.

import { useArrayReduce } from '@vueuse/core'

const sum = useArrayReduce([ref(1), ref(2), ref(3)], (sum, val) => sum + val)
// sum.value: 6

Use with reactive array

import { useArrayReduce } from '@vueuse/core'

const list = reactive([1, 2])
const sum = useArrayReduce(list, (sum, val) => sum + val)

list.push(3)
// sum.value: 6

Use with initialValue

import { useArrayReduce } from '@vueuse/core'

const list = reactive([{ num: 1 }, { num: 2 }])
const sum = useArrayReduce(list, (sum, val) => sum + val.num, 0)
// sum.value: 3

Additional context

Continue #1874

#1812 (comment)

Port from #1831

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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.