Style: Enforce separation line between function definitions

I couldn't find a tool that enforces it, so I went the manual route:
```
find -name "thirdparty" -prune \
  -o -name "*.cpp" -o -name "*.h" -o -name "*.m" -o -name "*.mm" \
  -o -name "*.glsl" > files
perl -0777 -pi -e 's/\n}\n([^#])/\n}\n\n\1/g' $(cat files)
misc/scripts/fix_style.sh -c
```

This adds a newline after all `}` on the first column, unless they
are followed by `#` (typically `#endif`). This leads to having lots
of places with two lines between function/class definitions, but
clang-format then fixes it as we enforce max one line of separation.

This doesn't fix potential occurrences of function definitions which
are indented (e.g. for a helper class defined in a .cpp), but it's
better than nothing. Also can't be made to run easily on CI/hooks so
we'll have to be careful with new code.

Part of #33027.

core/io/file_access_encrypted.cpp

@@ -113,6 +113,7 @@ Error FileAccessEncrypted::open_and_parse_password(FileAccess *p_base, const Str
 Error FileAccessEncrypted::_open(const String &p_path, int p_mode_flags) {
 	return OK;
 }
+
 void FileAccessEncrypted::close() {
 	if (!file)
 		return;
@@ -189,9 +190,11 @@ void FileAccessEncrypted::seek(size_t p_position) {
 void FileAccessEncrypted::seek_end(int64_t p_position) {
 	seek(data.size() + p_position);
 }
+
 size_t FileAccessEncrypted::get_position() const {
 	return pos;
 }
+
 size_t FileAccessEncrypted::get_len() const {
 	return data.size();
 }
@@ -211,6 +214,7 @@ uint8_t FileAccessEncrypted::get_8() const {
 	pos++;
 	return b;
 }
+
 int FileAccessEncrypted::get_buffer(uint8_t *p_dst, int p_length) const {
 	ERR_FAIL_COND_V_MSG(writing, 0, "File has not been opened in read mode.");