Re-organize Vue code #3: vue-ts mediator

[kevreth]

Create a mediator between the /src/vue/ and /src/ts/ directories.

This will entail:

1. Documenting all the imports of /src/ts/ into files under /src/vue/. Here's a sample before the /src/vue/ gets created in an earlier issue:

$ grep -nR "import" pages | grep "../ts/"
pages/IndexPage.vue:12:import { PREFIX_COURSE_FILE, switchCourse } from '../ts/main/quiz';
pages/IndexPage.vue:13:import {getCourseName, getYaml, setCourseListing, setCourseName} from '../ts/main/utilities';

$ grep -nR "import" components/ | grep "../ts/"
components/CourseSelector.vue:58:import { getCourseData } from '../ts/main/utilities';
components/CourseSelector.vue:61:import {switchCourse} from '../ts/main/quiz';
components/VolumeMute.vue:13:import { muteAudio, playBack } from '../ts/main/quiz/slide/audio';
components/MenuOverlay.vue:24:import {SaveData} from '../ts/main/quiz/datalayer/saveData';
components/ProgressTable.vue:69:import {Score} from '../ts/main/quiz/score';
components/ProgressTable.vue:70:import {CourseFile} from '../ts/main/quiz/datalayer/globals'

2. Creating a file, /src/vue/mediator.ts, what will take the imports above and export them. An excerpt:

import { getCourseData } from '../ts/main/utilities';
export getCourseData;

3. Update all files under /src/vue/ to import /src/vue/mediator.ts as appropriate.