Style: Partially apply clang-tidy's cppcoreguidelines-pro-type-member-init

Didn't commit all the changes where it wants to initialize a struct
with `{}`. Should be reviewed in a separate PR.

Option `IgnoreArrays` enabled for now to be conservative, can be
disabled to see if it proposes more useful changes.

Also fixed manually a handful of other missing initializations / moved
some from constructors.

modules/dds/texture_loader_dds.cpp

@@ -68,7 +68,7 @@ enum DDSFormat {
 };
 
 struct DDSFormatInfo {
-	const char *name;
+	const char *name = nullptr;
 	bool compressed = false;
 	bool palette = false;
 	uint32_t divisor = 0;