Add braces to C++ single-line loops and conditionals (NFC) (#2973)

This makes code easier to read and more consistent between C++ and Java.
Also update clang-format settings to always add a line break (even if no braces are used).

wpiutil/src/main/native/include/wpi/raw_istream.h

@@ -47,7 +47,9 @@ class raw_istream {
 
   size_t readsome(void* data, size_t len) {
     size_t readlen = (std::min)(in_avail(), len);
-    if (readlen == 0) return 0;
+    if (readlen == 0) {
+      return 0;
+    }
     read_impl(data, readlen);
     return m_read_count;
   }