fix: multiple usage of app header (#48)

Remove multiple usage of app header component and use the shell component
to route with shell, loading the header only once initially.

Fixes #47

src/app/clients/create-client/create-client.component.html

@@ -1,9 +1,8 @@
-<app-header> </app-header>
 <div class="container">
 
  <aw-wizard class="mt-5" #wizard [navBarLayout]="'large-empty-symbols'">
   <aw-wizard-step stepTitle="Title of step 1" [navigationSymbol]="{ symbol: '1' }">
-  
+
           <div class="col-sm-6 mx-auto">
               <div class="card mt-5">
     <div class="card-body">
@@ -13,41 +12,41 @@
             <input class="form-control" id="disabledInput" placeholder="Disabled input here..." disabled="" type="text">
           </fieldset>
         </div>
-        
+
         <div class="form-group">
           <fieldset>
             <label class="control-label" for="readOnlyInput">Readonly input</label>
             <input class="form-control" id="readOnlyInput" placeholder="Readonly input here…" readonly="" type="text">
           </fieldset>
         </div>
-        
+
         <div class="form-group has-success">
           <label class="form-control-label" for="inputSuccess1">Valid input</label>
           <input value="correct value" class="form-control is-valid" id="inputValid" type="text">
           <div class="valid-feedback">Success! You've done it.</div>
         </div>
-        
+
         <div class="form-group has-danger">
           <label class="form-control-label" for="inputDanger1">Invalid input</label>
           <input value="wrong value" class="form-control is-invalid" id="inputInvalid" type="text">
           <div class="invalid-feedback">Sorry, that username's taken. Try another?</div>
         </div>
-        
+
         <div class="form-group">
           <label class="col-form-label col-form-label-lg" for="inputLarge">Large input</label>
           <input class="form-control form-control-lg" placeholder=".form-control-lg" id="inputLarge" type="text">
         </div>
-        
+
         <div class="form-group">
           <label class="col-form-label" for="inputDefault">Default input</label>
           <input class="form-control" placeholder="Default input" id="inputDefault" type="text">
         </div>
-        
+
         <div class="form-group">
           <label class="col-form-label col-form-label-sm" for="inputSmall">Small input</label>
           <input class="form-control form-control-sm" placeholder=".form-control-sm" id="inputSmall" type="text">
         </div>
-        
+
         <div class="form-group">
           <label class="control-label">Input addons</label>
           <div class="form-group">
@@ -68,7 +67,7 @@
       </div>
     </div>
 
-    
+
   </aw-wizard-step>
   <aw-wizard-step stepTitle="Title of step 2" [navigationSymbol]="{ symbol: '2' }" >
       <div class="col-sm-6 mx-auto">
@@ -77,7 +76,7 @@
          -->    <div class="card-body">
               <form>
                 <fieldset>
-                  
+
                   <div class="form-group row">
                     <label for="staticEmail" class="col-sm-2 col-form-label">Email</label>
                     <div class="col-sm-10">