Refactor usage of deprecated ParameterBag code.

[dongilbert]

Q	A
Bug fix?	N
New feature?	N/A
Automated tests included?	N/A
Related user documentation PR URL	N/A
Related developer documentation PR URL	https://github.com/symfony/symfony/blob/3.0/UPGRADE-3.0.md#httpfoundation
Issues addressed (#s or URLs)	#8023
BC breaks?	N
Deprecations?	N

Description:

Removes deep item access from the request as documented in the symfony dev docs linked above.

Steps to test this PR:

1. Load up this PR
2. Test creating and editing throughout the app, specifically around

• Assets
• Campaigns
• Campaign Events
• Dynamic Content
• Emails
• Forms
• Form Actions
• Form Fields
• Companies
• Contacts
• Notifications
• Point Actions
• Point Triggers
• SMS
• Stages
• Profiles
• Roles
• Users
• Profile (your own user)
• Focus Items
• Social items (twitter monitoring)

[escopecz]

If I try to save a Mautic user form I get
500 Internal Server Error - PHP Notice - Array to string conversion in /vendor/symfony/security/Core/Encoder/EncoderFactory.php:51

Can you replicate? I checked that I can save that form on the m2-to-m3 branch with no error.

[dongilbert]

Was able to reproduce, thanks @escopecz. Fixed

[escopecz]

I got 500 Internal Server Error - Permission must be in the format of bundle:permission:level (i.e. user:users:view). 'plugin:focus:items:viewown' given. on the form action form and the focus item edit form but it's not related to this PR and I think that @hluchas fixed it already in another PR. Just noting it here as FYI.

Other than that everything worked.