diagnostics:add cpu arch (#9653)
diagnostics:add cpu arch (#9653)

Signed-off-by: Max-Cheng <e98bcc99fbf09a968d13df9e417d2ef32d334973@gmail.com>

What's Changed:

This PR implements the Diagnostics service server information retrieving interface, which is used to retrieve server load / hardware / system wide information. And this PR includes the following information:

- Hardware
  - CPU 
    - Arch

### Check List <!--REMOVE the items that are not applicable-->

Tests <!-- At least one of them must be included. -->

- Unit test

### Release note <!-- bugfixes or new feature need a release note -->
- Support display CPU arch
c4pt0r/tikv,BusyJay/tikv,BusyJay/tikv,BusyJay/tikv,BusyJay/tikv