CI: Adding basic formatting tests (#509)

better names

Using dedicated eclint image

Reconfiguring editorconfig

Removing intellij-specific configuration and making adjustments.

Final improvements

Minor improvements.

end_of_line = lf

Adding basic formatting tests.

Co-authored-by: 6543 <6543@obermui.de>
Reviewed-on: https://gitea.com/gitnex/GitNex/pulls/509
Reviewed-by: 6543 <6543@noreply.gitea.io>

.editorconfig

@@ -0,0 +1,17 @@
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 4
+indent_style = space
+insert_final_newline = true
+max_line_length = 150
+
+[*.java]
+indent_style = tab
+max_line_length = 220
+
+[*.json]
+indent_size = 2
+
+[{*.yml,*.yaml}]
+indent_size = 2