Disallow default parameters in parser/control type declarations

[Sanketjadhav31]

Fixes #5685

Summary

Disallow default parameter values in parser and control type declarations.

The frontend now reports a type error when a parser or control type declaration contains an apply parameter with a default value.

The existing control type test is moved from p4_16_samples to p4_16_errors, and a parser type regression test is added. Ordinary parser and control declarations with default parameters remain valid.

Tests

• ctest -R "err.*default-control-argument" --output-on-failure
• ctest -R "err.*issue5685-parser-default" --output-on-failure
• ctest -R "p4.*issue1333" --output-on-failure
• git diff HEAD --check

[ChrisDodd]

This doesn't really "disallow" control/parser types with default args as such -- it flags an error if you ever try to call something (a package, generally, as only packages can have control/parser types as args) that uses control/parser type with a default arg. You can still declare such types, and declare packages that take them as args, as long as you never try to instantiate said package. This may be good enough -- actually trying to flag an error when the control/parser type is created would also flag errors for simple controls and parsers that have default args (which should be ok).

@fruffy @jafingerhut any opinion as to whether this is an acceptable approach?