Throw exception when unable to normalize embedded object

Added a check to ensure that injected serializer of the
GetSetMethodNormalizer is a normalizer before normalizing object value.
bug #10306 [Serializer] Throw exception when unable to normalize embedded object (gquemener)

This PR was submitted for the 2.1 branch but it was merged into the 2.4 branch instead (closes #10306).

Discussion
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[Serializer] Throw exception when unable to normalize embedded object

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

This PR intends to prevent Fatal Error about calling undefined method `normalize()` on object `$serializer` in the `GetSetMethodNormalizer` when injected serializer does not implement the `NormalizerInterface`.

Commits
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8a54920 [Serializer] Throw exception when unable to normalize embedded object