rust: Improve code formatting

Do some formatting that are in experimental stage but improve the code
readability.

Use rustfmt with a nightly toolchain and enable:

format_code_in_doc_comments = true
reorder_impl_items = true
comment_width = 100
wrap_comments = true
normalize_comments = true

(see .rustfmt.toml)

Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>

rust/pvapconfig/src/config.rs

@@ -42,7 +42,8 @@ impl ApConfigEntry {
         }
         // if name is given, calculate sha256 digest for this name
         // test for the hash calculated here can be done with openssl:
-        // echo -n "Hello" >in.bin; openssl dgst -sha256 -binary -out out.bin in.bin; hexdump -C out.bin
+        // echo -n "Hello" >in.bin; openssl dgst -sha256 -binary -out out.bin in.bin; hexdump -C
+        // out.bin
         if self.name.is_empty() {
             return Ok(());
         }