Enabled csrf_protection by default if form.csrf_protection is enabled
bug #9662 [FrameworkBundle] Enabled csrf_protection by default if form.csrf_protection is enabled (bschussek)

This PR was submitted for the master branch but it was merged into the 2.4 branch instead (closes #9662).

Discussion
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[FrameworkBundle] Enabled csrf_protection by default if form.csrf_protection is enabled

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #9429
| License       | MIT
| Doc PR        | -

This PR enables the CSRF protection services automatically if CSRF protection for forms is enabled. In this case, the CSRF protection services cannot be disabled anymore manually (the same as with the validation services).

Commits
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b5e5c71 [FrameworkBundle] Enabled csrf_protection by default if form.csrf_protection is enabled