Enemies visible radius and behaviour

[Leo-Dev-2004]

• Enemies should try to walk either towards the CORE or an entity.
• Enemies should only have a visible range of 500 (with export variable so that you can control it)
• Enemies spawned by the EnemyManager in the main scene should be added to a new global Signal group "AttackingCore"
• The CORE needs a health bar aswell but much stronger (500HP (export variable), but only healing slowly unlike allies in small circle healing quickly)
• Enemies can attack the CORE so they attack not only entities but also the CORE in group CORE as well.

[Leo-Dev-2004]

@Benzooos @Sc0pes Habt ihr Bock das umzusetzen? Sollte recht easy sein. 👍