[php-symfony] Fixed a bug where Controller accessed non-existent prop…

[dimitriyremerov]

…erty

PR checklist

• [x] Read the contribution guidelines.
• [x] Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh and ./bin/security/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\.
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Description of the PR

This PR fixes https://github.com/swagger-api/swagger-codegen/issues/8337 The Controller must extend BaseController to be able to access container property.

cc @ksm2