Update the "Angular Universal SSR" example to Angular version 15

[ViniChab]

The Angular Universal SSR is currently using Angular version 10, we want to update it to version 15.

I'll be tackling this myself, this issue is here for documentation.

[ViniChab]

The PR for this issue is here (currently draft): #2717

More info about its progress can be found there

[belinef]

PR based on 2717
#2775