[person] Feature: add a person's center history

The association between Person and Center is now stored in a dedicated
Entity: `PersonCenterHistory`, which have a date interval (start date
and endDate). The SQL counterpart is a table, with a constraint which
ensure that no person might be associated with two center at the same time.

For ease, a view is created to get the current center associated with
the person.

The dedicated migration creates also:

* indexes for a rapid search for person at current date;
* and populate the table from current data, setting the startdate to the
  person's creation date and time if any, `NOW()` unless.

The `Person` entity is also updated to use the information from the
PersonCenterHistory classes, but this commit does not yet delete the
`Center` column.

src/Bundle/ChillPersonBundle/Entity/Person/PersonCenterCurrent.php

@@ -0,0 +1,112 @@
+<?php
+
+namespace Chill\PersonBundle\Entity\Person;
+
+use Chill\MainBundle\Doctrine\Model\TrackCreationInterface;
+use Chill\MainBundle\Doctrine\Model\TrackCreationTrait;
+use Chill\MainBundle\Doctrine\Model\TrackUpdateInterface;
+use Chill\MainBundle\Doctrine\Model\TrackUpdateTrait;
+use Chill\MainBundle\Entity\Center;
+use Chill\MainBundle\Entity\User;
+use Chill\PersonBundle\Entity\Person;
+use DateTimeInterface;
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * Associate a Person with the current center.
+ *
+ * The process of selecting the current center is done on database side,
+ * using a SQL view.
+ *
+ * @ORM\Entity(readOnly=true)
+ * @ORM\Table(name="view_chill_person_person_center_history_current")
+ * @psalm-internal Chill\PersonBundle\Entity
+ */
+class PersonCenterCurrent
+{
+    /**
+     * @ORM\Id
+     * @ORM\Column(type="integer")
+     */
+    private ?int $id = null;
+
+    /**
+     * @ORM\ManyToOne(targetEntity=Person::class, inversedBy="centerCurrent")
+     */
+    private Person $person;
+
+    /**
+     * @ORM\ManyToOne(targetEntity=Center::class)
+     */
+    private Center $center;
+
+    /**
+     * @ORM\Column(type="date_immutable", nullable=false)
+     */
+    private \DateTimeImmutable $startDate;
+
+    /**
+     * @ORM\Column(type="date_immutable", nullable=true, options={"default": null})
+     */
+    private ?\DateTimeImmutable $endDate = null;
+
+    /**
+     * Populate the properties person, center, start and end date from history.
+     *
+     * The creator and updatedby are not filled.
+     *
+     * @internal Should not be instantied, unless inside Person entity
+     * @param PersonCenterHistory $history
+     */
+    public function __construct(PersonCenterHistory $history)
+    {
+        $this->person = $history->getPerson();
+        $this->center = $history->getCenter();
+        $this->startDate = $history->getStartDate();
+        $this->endDate = $history->getEndDate();
+        $this->id = $history->getId();
+    }
+
+    /**
+     * The id will be the same as the current @link{PersonCenterHistory::class}
+     *
+     * @return int
+     */
+    public function getId(): int
+    {
+        return $this->id;
+    }
+
+    /**
+     * @return Person
+     */
+    public function getPerson(): Person
+    {
+        return $this->person;
+    }
+
+    /**
+     * @return Center
+     */
+    public function getCenter(): Center
+    {
+        return $this->center;
+    }
+
+    /**
+     * @return \DateTimeImmutable
+     */
+    public function getStartDate(): \DateTimeImmutable
+    {
+        return $this->startDate;
+    }
+
+    /**
+     * @return \DateTimeImmutable|null
+     */
+    public function getEndDate(): ?\DateTimeImmutable
+    {
+        return $this->endDate;
+    }
+
+}