[WorkManager] Better Kotlin DSL for `Data`

```kotlin
val workData = buildData {
// Perhaps we can have similar utilities to that of a MutableMap?
this += "key" to 123
this += workDataOf(/* ... */) // Add existing data
addData {
// Add data from a Data.Builder
putBoolean("abc", false)
}

this -= workDataOf(/* ... */) // Remove the mutable data's properties that are present in the specified Data
}
```