Show pipeline created time in pipeline header

What does this MR do and why?

With the new pipeline header we were only showing pipeline finished time. We got some feedback that the "triggered" time (createdAt) was useful for long running pipelines. This MR adds back the created at time ago for the pipeline as well as keeps the finished time of the pipeline.

I have also added the strings created and finished to differentiate these two times since they could get easily confused.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

Finished example

How to set up and validate locally

1. Visit project with pipeline
2. Run a pipeline, you should see created at time
3. Visit finished pipeline, you should see finished time

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.

Related to #416136 (closed)

app/assets/javascripts/pipelines/components/pipelines_list/time_ago.vue

@@ -14,11 +14,6 @@ export default {
       type: Object,
       required: true,
     },
-    displayCalendarIcon: {
-      type: Boolean,
-      required: false,
-      default: true,
-    },
     fontSize: {
       type: String,
       required: false,
@@ -50,13 +45,7 @@ export default {
     </p>
 
     <p v-if="finishedTime" class="finished-at gl-display-inline-flex gl-align-items-center">
-      <gl-icon
-        v-if="displayCalendarIcon"
-        name="calendar"
-        class="gl-mr-2"
-        :size="12"
-        data-testid="calendar-icon"
-      />
+      <gl-icon name="calendar" class="gl-mr-2" :size="12" data-testid="calendar-icon" />
 
       <time
         v-gl-tooltip