[#1936] Migrate c-segment-collection.vue to typescript (#2036)

Currently, there is still some JavaScript code which remains unmigrated.
This allows for type unsafe code to be written, potentially resulting in
unintended behavior.

Let's migrate the rest of the JavaScript code to TypeScript code to
facilitate future changes to the code.

frontend/src/components/c-segment-collection.vue

@@ -4,17 +4,19 @@
  c-segment(v-bind:segment="segment", v-bind:path="path")
 </template>
 
-<script>
+<script lang='ts'>
+import { defineComponent } from 'vue';
 import cSegment from './c-segment.vue';
+import Segment from '../utils/segment';
 
-export default {
+export default defineComponent({
  name: 'c-segment-collection',
  components: {
  cSegment,
  },
  props: {
  segments: {
- type: Array,
+ type: Array<Segment>,
  required: true,
  },
  path: {
@@ -28,11 +30,11 @@ export default {
  };
  },
  methods: {
- visibilityChanged(isVisible) {
+ visibilityChanged(isVisible: boolean) {
  if (isVisible) {
  this.isRendered = true;
  }
  },
  },
-};
+});
 </script>