[interp] break up MINT_LDSTR_TOKEN into two opcodes (#88738)

[interp] break up MINT_LDSTR_TOKEN into two opcodes (#88738)

MINT_LDSTR_DYNAMIC for dynamic methods.  the data item is an index
into the DynamicMethod:method.method_data which stores pointers to
MonoString objects that are held by the managed DynamicMethod.

MINT_LDSTR_CSTR for ilgen wrappers. the data item is a raw C string
that is global, or was allocated by malloc

Fixes https://github.com/dotnet/runtime/issues/88694 by allowing
MINT_LDSTR_CSTR in any method since we no longer depend on
mono_method_get_wrapper_data at execution time.  And at transform time
we have access to the actual wrapper method.