[FrameworkBundle][Translation] moved cache to Translation component

[Translation][Cache] removed accessors for options.
[Translation][Cache] Removed the options from the arguments of Translator

Fixed phpdoc

Aligned variables and description

Removed enableCache and added cache setup in constructor

Added tests for locales with . and @ with caching
feature #11373 [FrameworkBundle][Translation] moved cache to Translation component (new PR) (aitboudad, OwlyCode)

This PR was merged into the 2.6-dev branch.

Discussion
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[FrameworkBundle][Translation] moved cache to Translation component (new PR)

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #10628
| License       | MIT
| Doc PR        |

This supersedes the PR #11197 (while including the changes made by it). I removed the `$options` argument for `Symfony\Component\Translation\Translator` and replaced it by a public method `enableCache($cacheDir, $debug = false)`. It aims to solve what @fabpot said about passing an array of options in #11197 
while not modifying the existing constructors
.

Commits
-------

30fed6a [Translation][Cache] Removed the options from the arguments of Translator
8b2d9a8 [FrameworkBundle][Translation] moved cache to Translation component