Changing scale changes getBounds() in Text with autoScaling = true

The same is not true of other views, e.g. SolidRect

Barebones repro:
```
class TestScene : Scene() {
override suspend fun Container.sceneInit() {
val left = 200
val right = 700

val redBox = solidRect(100, 100, Colors.RED) {
xy(500, 500)
}
val text = text("This is a Message") {
xy(left, 200)
fontSize = 32.0
}
println("redBox")
println("bounds = ${redBox.getBounds()}")
redBox.scale = 0.2
println("==0.2==")
println("bounds = ${redBox.getBounds()}")
redBox.scale = 2.0
println("==2.0==")
println("bounds = ${redBox.getBounds()}")
redBox.scale = 1.0
println("==1.0==")
println("bounds = ${redBox.getBounds()}")
println("=default==")
println("bounds = ${text.getBounds()}")
text.scale = 0.2
println("==0.2==")
println("bounds = ${text.getBounds()}")
text.scale = 2.0
println("==2.0==")
println("bounds = ${text.getBounds()}")
text.scale = 1.0
println("==1.0==")
println("bounds = ${text.getBounds()}")
}
```

Output:
```
redBox
bounds = Rectangle(x=0, y=0, width=100, height=100)
==0.2==
bounds = Rectangle(x=0, y=0, width=100, height=100)
==2.0==
bounds = Rectangle(x=0, y=0, width=100, height=100)
==1.0==
bounds = Rectangle(x=0, y=0, width=100, height=100)
=default==
bounds = Rectangle(x=0.7486979166666667, y=0, width=233.7391304347826, height=31.304347826086957)
==0.2==
bounds = Rectangle(x=0.14973958333333334, y=0, width=250.43478260869566, height=41.73913043478261)
==2.0==
bounds = Rectangle(x=1.4973958333333335, y=0, width=231.65217391304347, height=29.217391304347824)
==1.0==
bounds = Rectangle(x=0.7486979166666667, y=0, width=233.7391304347826, height=31.304347826086957)
```

See also: https://kotlinlang.slack.com/archives/CJEF0LB6Y/p1610396895392300

Start by running the barebones TestScene reproduction and comparing Text with SolidRect, whose getBounds() output remains unchanged when scaled. Then trace the Text autoScaling and getBounds() implementation; done means Text bounds behave consistently when scale changes, with regression coverage for the reported outputs.

Written by the indexing model from the issue text.