tsk-1371 Support indent for specials (#3128)

Signed-off-by: Denis Bunakalya <denis.bunakalya@xored.com>

plugins/workbench-resources/src/components/Navigator.svelte

@@ -151,6 +151,7 @@
               icon={special.icon}
               selected={menuSelection ? false : special.id === currentSpecial}
               {disabled}
+              indent={special.nestingLevel === 1 ? 'ml-2' : (special.nestingLevel === 2 && 'ml-4') || undefined}
             />
           </NavLink>
         {/await}

plugins/workbench/src/index.ts

@@ -85,6 +85,7 @@ export interface SpecialNavModel {
   // If defined, will be used to find spaces for visibleIf
   spaceClass?: Ref<Class<Space>>
   checkIsDisabled?: Resource<() => Promise<boolean>>
+  nestingLevel?: number
 }
 
 /**