added template support to echo

replaced HashMaps for templates with concrete models, so the interface is easier known
added rendering method for objects directly
added default parameters available for commands
split up service beans for server/channel into management and service bean
added server reference in AChannel
refactored join/leave listener

abstracto-application/templating/templating-impl/src/main/java/dev/sheldan/abstracto/templating/loading/DatabaseTemplateLoader.java

@@ -18,12 +18,7 @@ public class DatabaseTemplateLoader implements TemplateLoader {
 
     @Override
     public Object findTemplateSource(String s) throws IOException {
-        TemplateDto templateDtoByKey = templateService.getTemplateByKey(s);
-        if(templateDtoByKey != null){
-            return templateDtoByKey;
-        } else {
-            return null;
-        }
+        return templateService.getTemplateByKey(s);
     }
 
     @Override

abstracto-application/templating/templating-impl/src/main/java/dev/sheldan/abstracto/templating/loading/TemplateServiceBean.java

@@ -4,6 +4,7 @@ import dev.sheldan.abstracto.templating.TemplateDto;
 import dev.sheldan.abstracto.templating.TemplateService;
 import freemarker.template.Configuration;
 import freemarker.template.TemplateException;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.cache.annotation.Cacheable;
 import org.springframework.stereotype.Component;
@@ -13,6 +14,7 @@ import java.io.IOException;
 import java.time.Instant;
 import java.util.HashMap;
 
+@Slf4j
 @Component
 public class TemplateServiceBean implements TemplateService {
 
@@ -37,10 +39,18 @@ public class TemplateServiceBean implements TemplateService {
     public String renderTemplate(String key, HashMap<String, Object> parameters) {
         try {
             return FreeMarkerTemplateUtils.processTemplateIntoString(configuration.getTemplate(key), parameters);
-        } catch (IOException e) {
-            e.printStackTrace();
-        } catch (TemplateException e) {
-            e.printStackTrace();
+        } catch (IOException | TemplateException e) {
+            log.warn("Failed to render template: {}", e.getMessage());
+        }
+        return "";
+    }
+
+    @Override
+    public String renderTemplate(String key, Object model) {
+        try {
+            return FreeMarkerTemplateUtils.processTemplateIntoString(configuration.getTemplate(key), model);
+        } catch (IOException | TemplateException e) {
+            log.warn("Failed to render template: {}", e.getMessage());
         }
         return "";
     }

abstracto-application/templating/templating-impl/src/main/java/dev/sheldan/abstracto/templating/seeding/TemplateSeedDataLoader.java

@@ -1,4 +1,4 @@
-package dev.sheldan.abstracto.templating.seeddata;
+package dev.sheldan.abstracto.templating.seeding;
 
 import dev.sheldan.abstracto.templating.TemplateService;
 import org.apache.commons.io.FilenameUtils;