[clang-format] Fix template arguments in macros

Fixes https://github.com/llvm/llvm-project/issues/57738

old
```
#define FOO(typeName, realClass)                               \
  {                                                            \
#typeName, foo < FooType>(new foo <realClass>(#typeName))  \
  }
```
new
```
#define FOO(typeName, realClass)                                \
  { #typeName, foo<FooType>(new foo<realClass>(#typeName)) }
```

Previously, when an UnwrappedLine began with a hash in a macro
definition, the program incorrectly assumed the line was a preprocessor
directive.  It should be stringification.

The rule in spaceRequiredBefore was added in 8b529711.  Its purpose is
to add a space in an include directive.  It also added a space to a
template opener when the line began with a stringification hash.  So we
changed it.

Reviewed By: HazardyKnusperkeks, owenpan

Differential Revision: https://reviews.llvm.org/D133954