[General] remove symfony/symfony dependency

[craigh]

remove symfony/symfony dependency and replace with only needed components.

this is required as part of https://symfony.com/doc/current/setup/flex.html

at least

but also, just good practice and also current best-practice.

[Guite]

isn't this necessarily for 4.0.0 ?
because if we remove something this is a BC break

[craigh]

the goal would be to not remove anything 😄

I believe this simply done.

[Guite]

Then the description above is misleading:

replace with only needed components

[craigh]

possible you are right. I've done some preliminary research. As far as I can tell, the core is not using

• component/browser-kit // used in functional tests
• component/css-selector // used in functional tests
• component/dom-crawler // used in functional tests
• component/http-client ?? no? maybe used in functional tests?
• component/inflector
• component/ldap
• component/lock
• component/process ??
• component/property-access
• component/property-info
• component/serializer
• component/stopwatch
• component/templating (maybe used by maker?)
• component/var-dumper
• component/var-exporter
• component/web-link