refractor: accounting module (#300)

* Refractor components.
* Add resolvers.
* Add relative router links.
* Replace mat-icons by font-awesome icons.
* Add comments.

Fixes: #298

src/app/accounting/chart-of-accounts/create-gl-account/create-gl-account.component.scss

@@ -1,7 +1,7 @@
-.manualEntriesAllowedWrapper {
+.manual-entries-allowed-wrapper {
   position: relative;
 
-  .manualEntriesAllowed {
+  .manual-entries-allowed {
     padding: 0 0 17.5px 0;
     position: absolute;
     bottom: 0;