Import Groups page: Add icon with tooltip to table header

What does this MR do and why?

Introduces the following small UX changes to the table that's being used when importing groups:

• Renames the first column from From source group to Source group.
• Renames the second column from To destination group to New group.
• Adds an info icon + tooltip to the second column. On hover, the text Path of the new group is displayed.

Screenshots or screen recordings

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

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

Related to #367430 (closed)

app/assets/javascripts/import_entities/import_groups/components/import_table.vue

@@ -10,6 +10,7 @@ import {
   GlSprintf,
   GlTable,
   GlFormCheckbox,
+  GlTooltipDirective,
 } from '@gitlab/ui';
 import { debounce } from 'lodash';
 import { createAlert } from '~/flash';
@@ -60,7 +61,9 @@ export default {
     PaginationBar,
     HelpPopover,
   },
-
+  directives: {
+    GlTooltip: GlTooltipDirective,
+  },
   props: {
     sourceUrl: {
       type: String,
@@ -118,14 +121,14 @@ export default {
     },
     {
       key: 'webUrl',
-      label: s__('BulkImport|From source group'),
+      label: s__('BulkImport|Source group'),
       thClass: `${DEFAULT_TH_CLASSES} gl-pl-0! import-jobs-from-col`,
       // eslint-disable-next-line @gitlab/require-i18n-strings
       tdClass: `${DEFAULT_TD_CLASSES} gl-pl-0!`,
     },
     {
       key: 'importTarget',
-      label: s__('BulkImport|To new group'),
+      label: s__('BulkImport|New group'),
       thClass: `${DEFAULT_TH_CLASSES} import-jobs-to-col`,
       tdClass: DEFAULT_TD_CLASSES,
     },
@@ -665,6 +668,9 @@ export default {
               @change="hasAllAvailableGroupsSelected ? clearSelected() : selectAllRows()"
             />
           </template>
+          <template #head(importTarget)="data">
+            <span class="gl-mr-2">{{ data.label }}</span><gl-icon name="information" :size="12" v-gl-tooltip="s_('BulkImport|The path of the new group.')"/>
+          </template>
           <template #cell(selected)="{ rowSelected, selectRow, unselectRow, item: group }">
             <gl-form-checkbox
               class="gl-h-7 gl-pt-3"