Add unit test for full FRU decode

To start refactoring this, it is helpful if we have a representative
unit test that decodes a full FRU.

To simplify this, the internal interfaces have been updated to support
passing values by std::span<const uint8_t> instead of by reference to
std::vector.

Tested: Unit tests pass

Change-Id: If8a618969b99d3d8a32bc7203aa2f57d0f999bdf
Signed-off-by: Ed Tanous <etanous@nvidia.com>
diff --git a/meson.build b/meson.build
index f789a0d..cc5a78e 100644
--- a/meson.build
+++ b/meson.build
@@ -160,7 +160,7 @@
             'src/fru_utils.cpp',
             'src/fru_reader.cpp',
             cpp_args: test_boost_args,
-            dependencies: [boost, gtest, phosphor_logging_dep, sdbusplus],
+            dependencies: [boost, gtest, gmock, phosphor_logging_dep, sdbusplus],
             include_directories: 'src',
         ),
     )