Refactor to use new version of OEM IPMI Handler

Using the new version of ipmi handler provide a higher level wrapper
over the same functionalities. It helps us parse the input and output to
have more control of the input/output we see.

Changes to note,
- All cmd are removed from the request data. That is automatically
  extracted now.

Tested:
Unit Test Passed.

All IPMI OEM command still works the same as before this change.

```
$ burn_my_bmc -command stage -image /tmp/test.txt -interface ipmipci
Set up ipmi flash updater with /flash/dummy
Received failure on delete: Received IPMI_CC: 255
Sending over the firmware image.
Find [0x1050 0x750]
bar0[0x94000000]
Upload to BMC 100% |Goooooooooooooooooooooooooooooooooooooooooooooooooooooooogle| Time: 00:00:00
Opening the verification file
Committing to /flash/verify to trigger service
Calling stat on /flash/verify session to check status
success
succeeded
```

Also tested gBMC Update workflow which worked fine.

Change-Id: Ib2bfeab0c2ec5aa72ede1ff457ef5f90e488053c
Signed-off-by: Willy Tu <wltu@google.com>
diff --git a/test/meson.build b/test/meson.build
index db240b3..b5bdd99 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -37,6 +37,7 @@
     executable(
       t.underscorify(),
       t + '.cpp',
+      'helper.cpp',
       implicit_include_directories: false,
       dependencies: [blob_manager_dep, gtest, gmock]))
 endforeach