[ClamAV] Move to official ClamAV Docker container (#4525)

Since ClamAV starts to offer Docker containers this PR introduces said containers so we don't need to build the container on our own anymore. This was an easy task until v0.104, but then ClamAV changed its buildprocess to use cmake and with v0.105 it also needs the Rust toolchain -> https://docs.clamav.net/manual/Installing/Installing-from-source-Unix.html#ubuntu--debian

Here are the main changes for the new container

Creates clamd-db-vol-1 volume
Still uses the same config files
Downloads ClamAV databases in said volume
Smaller container footprint 13MB vs 150MB

---

* [ClamAV] Move to official ClamAV Docker container

* [ClamAV] Remove vim + nano

* [ClamAV] Use normal version in docker-compose

docker-compose.yml

@@ -58,7 +58,7 @@ services:
             - redis
 
     clamd-mailcow:
-      image: mailcow/clamd:1.44
+      image: mailcow/clamd:1.50
       restart: always
       dns:
         - ${IPV4_NETWORK:-172.22.1}.254
@@ -67,6 +67,7 @@ services:
         - SKIP_CLAMD=${SKIP_CLAMD:-n}
       volumes:
         - ./data/conf/clamav/:/etc/clamav/:Z
+        - clamd-db-vol-1:/var/lib/clamav:z
       networks:
         mailcow-network:
           aliases:
@@ -631,3 +632,4 @@ volumes:
   crypt-vol-1:
   sogo-web-vol-1:
   sogo-userdata-backup-vol-1:
+  clamd-db-vol-1: