fix: enhance layout structure in playbook builder component for better responsiveness

Author: mjabascal10

frontend/src/app/incident-response/playbook-builder/playbook-builder.component.css

@@ -1,3 +1,11 @@
+:host{
+  display: flex;
+  flex-direction: column;
+  flex: 1 1 auto;
+  min-height: 0;
+  height: 100%;
+}
+
 .sidebar-section {
   position: sticky;
   align-self: start;
@@ -11,3 +19,8 @@
   border-top: 1px solid #e0e0e0!important;
   z-index: 10;
 }
+
+.container-fluid {
+  flex: 1;
+  min-height: 0;
+}

frontend/src/app/incident-response/playbook-builder/playbook-builder.component.html

@@ -1,5 +1,4 @@
-
-<div class="container-fluid pr-3 pl-3 pt-2">
+<div class="container-fluid pr-2 pl-2 pt-2 d-flex flex-column">
   <div class="d-flex justify-content-between align-items-center mb-2 px-1">
     <h5 class="card-title mb-0 text-uppercase label-header">Add flow</h5>
     <div class="header-elements">