Add a button to Web IDE for returning to previous product page

What does this MR do and why?

Adds a button to the Web IDE to help the user return to the page that they launched the Web IDE from.

The root cause for this is that the back button navigates back to the last tab open if there are multiple tabs opened by the user. The new button allows a direct way for users to navigate back to the launching page.

This was raised in the Q1FY23 Create stage benchmarking study and past issues too.

Changes

• Add icon button with go-back icon
  • When the previous page is in a page from the GitLab product, then the button navigates the user to that page.
  • When the previous page is an external website, then the go-back button takes the user to project root.
• Project icon changes size from 48 to 32

Relates to #358597 (closed)

Screenshots or screen recordings

Current	Updated

Video

web-ide-back

How to set up and validate locally

1. Open the Web IDE
2. Open a few tabs
3. Pressing on the go-back button takes the user back to the page they opened the Web IDE from.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

app/assets/javascripts/ide/components/activity_bar.vue

@@ -9,6 +9,12 @@ export default {
     GlIcon,
     GlBadge,
   },
+  props: {
+    project: {
+      type: Object,
+      required: true,
+    },
+  },
   directives: {
     GlTooltip: GlTooltipDirective,
   },
@@ -24,6 +30,13 @@ export default {
 
       this.$root.$emit(BV_HIDE_TOOLTIP);
     },
+    navigateToPreviousPage() {
+      let previousPageUrl = this.project.web_url;
+      if (document.referrer) {
+        previousPageUrl = document.referrer;
+      }
+      window.location.href = previousPageUrl;
+    },
   },
   leftSidebarViews,
 };
@@ -32,6 +45,21 @@ export default {
 <template>
   <nav class="ide-activity-bar" data-testid="left-sidebar">
     <ul class="list-unstyled">
+      <li>
+        <button
+          v-gl-tooltip.right.viewport
+          :title="s__('IDE|Go back')"
+          :aria-label="s__('IDE|Go back')"
+          data-container="body"
+          data-placement="right"
+          data-testid="ide-return-btn"
+          type="button"
+          class="ide-sidebar-link"
+          @click="navigateToPreviousPage()"
+        >
+          <gl-icon name="go-back" />
+        </button>
+      </li>
       <li>
         <button
           v-gl-tooltip.right.viewport