types(computed): allow computed getter and setter types to be unrelated

[Alfred-Skyblue]

resolve #7271

In certain cases, we would like the computed property's getter and setter to have different types. This would provide added convenience in our usage, such as having the getter return a string while the setter accepts an object. In this PR, I have added a second generic parameter to the computed property to specify the type of the setter. With this enhancement, we can set different types for the getter and setter of computed using the following approach.

Examples:

const obj = ref({
  name: 'foo'
})

const newObj = computed<string, typeof obj.value>({
  get() {
    return JSON.stringify(obj.value)
  },
  set(val) {
    obj.value = val
  }
})
console.log(newObj.value) // string

newObj.value = { name: 'bar' } // object

[github-actions]

Size Report

Bundles

File	Size	Gzip	Brotli
runtime-dom.global.prod.js	97.3 kB (+7.2 kB)	37 kB (+2.41 kB)	33.3 kB (+2.13 kB)
vue.global.prod.js	155 kB (+8.16 kB)	56.7 kB (+2.7 kB)	50.5 kB (+2.43 kB)

Usages

Name	Size	Gzip	Brotli
createApp	53.8 kB (+4.19 kB)	20.9 kB (+1.38 kB)	19 kB (+1.21 kB)
createSSRApp	57.8 kB (+4.57 kB)	22.5 kB (+1.52 kB)	20.4 kB (+1.34 kB)
defineCustomElement	57.2 kB (+5.26 kB)	22 kB (+1.73 kB)	20 kB (+1.52 kB)
overall	67.4 kB (+4.25 kB)	25.9 kB (+1.39 kB)	23.5 kB (+1.25 kB)