fw-update: Break circular dependency

```
In file included from ../pldmd/pldmd.cpp:2:
In file included from ../common/flight_recorder.hpp:3:
In file included from ../common/utils.hpp:15:
In file incl

fw-update: Break circular dependency

```
In file included from ../pldmd/pldmd.cpp:2:
In file included from ../common/flight_recorder.hpp:3:
In file included from ../common/utils.hpp:15:
In file included from ../subprojects/nlohmann_json/single_include/nlohmann/json.hpp:29:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/memory:78:
/usr/bin/../lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/bits/unique_ptr.h:91:16: error: invalid application of 'sizeof' to an incomplete type 'pldm::fw_update::Activation'
91 | static_assert(sizeof(_Tp)>0,
| ^~~~~~~~~~~
/usr/bin/../lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/bits/unique_ptr.h:398:4: note: in instantiation of member function 'std::default_delete<pldm::fw_update::Activation>::opera
tor()' requested here
398 | get_deleter()(std::move(__ptr));
| ^
../fw-update/update_manager.hpp:46:14: note: in instantiation of member function 'std::unique_ptr<pldm::fw_update::Activation>::~unique_ptr' requested here
46 | explicit UpdateManager(
| ^
../fw-update/update_manager.hpp:33:7: note: forward declaration of 'pldm::fw_update::Activation'
33 | class Activation;
| ^
In file included from ../pldmd/pldmd.cpp:2:
In file included from ../common/flight_recorder.hpp:3:
In file included from ../common/utils.hpp:15:
In file included from ../subprojects/nlohmann_json/single_include/nlohmann/json.hpp:29:
In file included from /usr/bin/../lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/memory:78:
/usr/bin/../lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/bits/unique_ptr.h:91:16: error: invalid application of 'sizeof' to an incomplete type 'pldm::fw_update::ActivationProgress'
91 | static_assert(sizeof(_Tp)>0,
| ^~~~~~~~~~~
/usr/bin/../lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/bits/unique_ptr.h:398:4: note: in instantiation of member function 'std::default_delete<pldm::fw_update::ActivationProgress
>::operator()' requested here
398 | get_deleter()(std::move(__ptr));
| ^
../fw-update/update_manager.hpp:46:14: note: in instantiation of member function 'std::unique_ptr<pldm::fw_update::ActivationProgress>::~unique_ptr' requested here
46 | explicit UpdateManager(
| ^
../fw-update/update_manager.hpp:34:7: note: forward declaration of 'pldm::fw_update::ActivationProgress'
34 | class ActivationProgress;
| ^
```

Change-Id: I2820cbe134d1f37a43e6a5056eed87dde6e63b08
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>

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