Add post and species forms

Squashed commit of the following:
Author: Hugo PRADIER <Hugo.PRADIER2@etu.uca.fr>
Author: bastien ollier <bastien.ollier@etu.uca.fr>
Author: clfreville2 <clement.freville2@etu.uca.fr>
Reviewed on #7

src/Entity/Species.php

@@ -9,6 +9,7 @@ use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
 use Symfony\Component\Serializer\Attribute\Groups;
+use Symfony\Component\Validator\Constraints as Assert;
 
 #[ORM\Entity(repositoryClass: SpeciesRepository::class)]
 #[ApiResource(
@@ -26,14 +27,17 @@ class Species
 
     #[ORM\Column(length: 255)]
     #[Groups(['species:collection:read'])]
+    #[Assert\NotBlank]
     private ?string $scientific_name = null;
 
     #[ORM\Column(length: 255)]
     #[Groups(['species:collection:read'])]
+    #[Assert\NotBlank]
     private ?string $vernacular_name = null;
 
     #[ORM\Column(length: 255)]
     #[Groups(['species:collection:read'])]
+    #[Assert\NotBlank]
     private ?string $region = null;
 
     /**