feature #15013 [Security] Removed security-acl from the core (iltar)

This PR was squashed before being merged into the 2.8 branch (closes #15013).

Discussion
----------

[Security] Removed security-acl from the core

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | part of #14718
| License       | MIT
| Doc PR        | ~

The `Security\Acl` is removed from the core and is loaded from its own repository. All tests were passing and this is fully backwards compatible. I have removed all but the Test files in the first step and added the dependency to verify the Test were still working with the package dependency. The second step was to remove the remaining test files and tests are still running for both the Bundle and the Framework. Once the Read-Only repository is a full standalone repository, this PR can be merged.

- [x] Remove component from the core
- [ ] Remove read-only from https://github.com/symfony/security-acl

Once this PR is merged, I can start working on splitting the SecurityBundle and extracting the ACL part to the AclBundle.

/cc @fabpot

Commits
-------

b26a449 [Security] Removed security-acl from the core

1 files changed, 0 insertions, 35 deletions

diff --git a/Acl/Model/SecurityIdentityRetrievalStrategyInterface.php b/Acl/Model/SecurityIdentityRetrievalStrategyInterface.php
deleted file mode 100644
index b5fcb75..0000000
--- a/Acl/Model/SecurityIdentityRetrievalStrategyInterface.php
+++ /dev/null
@@ -1,35 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\Security\Acl\Model;
-
-use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
-
-/**
- * Interface for retrieving security identities from tokens.
- *
- * @author Johannes M. Schmitt <schmittjoh@gmail.com>
- */
-interface SecurityIdentityRetrievalStrategyInterface
-{
-    /**
-     * Retrieves the available security identities for the given token.
-     *
-     * The order in which the security identities are returned is significant.
-     * Typically, security identities should be ordered from most specific to
-     * least specific.
-     *
-     * @param TokenInterface $token
-     *
-     * @return SecurityIdentityInterface[] An array of SecurityIdentityInterface implementations
-     */
-    public function getSecurityIdentities(TokenInterface $token);
-}