Implement custom lightweight modal #230

Introduce a brand new lightweight and efficient modal component. It is
designed to be visually similar to the previous one to not introduce a
change in feel of the application in a patch release, but behind the
scenes it features:

- Enhanced application speed and reduced bundle size.
- New flexbox-driven layout, eliminating JS calculations.
- Composition API ready for Vue 3.0 #230.

Other changes:

- Adopt idiomatic Vue via `v-modal` binding.
- Add unit tests for both the modal and dialog.
- Remove `vue-js-modal` dependency in favor of the new implementation.
- Adjust modal shadow color to better match theme.
- Add `@vue/test-utils` for unit testing.

package.json

@@ -8,7 +8,7 @@
   "scripts": {
     "serve": "vue-cli-service serve",
     "build": "vue-cli-service build",
-    "test:unit": "vue-cli-service test:unit",
+    "test:unit": "vue-cli-service test:unit --include ./tests/bootstrap/setup.ts",
     "test:e2e": "vue-cli-service test:e2e",
     "lint": "npm run lint:md && npm run lint:md:consistency && npm run lint:md:relative-urls && npm run lint:eslint && npm run lint:yaml",
     "create-icons": "node img/logo-update.mjs",
@@ -21,7 +21,7 @@
     "lint:yaml": "yamllint **/*.yaml --ignore=node_modules/**/*.yaml",
     "postinstall": "electron-builder install-app-deps",
     "postuninstall": "electron-builder install-app-deps",
-    "test:integration": "vue-cli-service test:unit \"tests/integration/**/*.spec.ts\""
+    "test:integration": "vue-cli-service test:unit \"tests/integration/**/*.spec.ts\" --include ./tests/bootstrap/setup.ts"
   },
   "main": "index.js",
   "dependencies": {
@@ -41,8 +41,7 @@
     "markdown-it": "^13.0.1",
     "npm": "^9.8.1",
     "v-tooltip": "2.1.3",
-    "vue": "^2.7.14",
-    "vue-js-modal": "^2.0.1"
+    "vue": "^2.7.14"
   },
   "devDependencies": {
     "@rushstack/eslint-patch": "^1.3.2",
@@ -60,6 +59,7 @@
     "@vue/cli-service": "~5.0.8",
     "@vue/eslint-config-airbnb-with-typescript": "^7.0.0",
     "@vue/eslint-config-typescript": "^11.0.3",
+    "@vue/test-utils": "^1.3.6",
     "chai": "^4.3.7",
     "cypress": "^12.17.2",
     "electron": "^25.3.2",