rename ee10 packages to servlet6

[lachlan-roberts]

it would be good to rename some of the packages from ee10 to servlet6

We will soon have ee11 with servlet 6.1, so would be nice if we didn't need an ee11 package

[ludoch]

We should do that before GA, when possible

[ludoch]

But do you think whenever we java a package with jetty ee10, we need to keep the one from GAE using it?
Or will you refactor some jetty ee10 packages/modules to jetty servlet6?
Which ones?