Allow word format as variable name in templates

[mkurz]

Fixes

• Value Raw is not a member of String error with variable named format present #112

[mkurz]

As expected:

 [info] - should compile successfully when using 'format' as variable name *** FAILED ***
[info]   play.twirl.compiler.test.Helper$CompilationError: value raw is not a member of String
[info]   at play.twirl.compiler.test.Helper$CompilerHelper.$anonfun$compile$1(Helper.scala:117)
[info]   at scala.Option.foreach(Option.scala:407)
[info]   at play.twirl.compiler.test.Helper$CompilerHelper.compile(Helper.scala:114)
[info]   at play.twirl.compiler.test.CompilerSpec.$anonfun$new$65(CompilerSpec.scala:1008)
[info]   at org.scalatest.OutcomeOf.outcomeOf(OutcomeOf.scala:85)
[info]   at org.scalatest.OutcomeOf.outcomeOf$(OutcomeOf.scala:83)
[info]   at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
[info]   at org.scalatest.Transformer.apply(Transformer.scala:22)
[info]   at org.scalatest.Transformer.apply(Transformer.scala:20)
[info]   at org.scalatest.wordspec.AnyWordSpecLike$$anon$3.apply(AnyWordSpecLike.scala:1240)

[mkurz]

Fixed.
fyi: Play needs to bump to this twirl version because play compiles some default twirl pages like error.scala.html, so those artifacts need to be updated to use the new variable $twirl__format.