chore: update dependencies and refactor Vuex store for country data

- Updated dependencies in package.json to latest versions for axios, bulma, core-js, vue, vuex, and testing libraries.
- Refactored actions.js to use the new REST Countries API v3 with a fallback to v2, improving error handling and data mapping.
- Simplified Vuex store structure by defining state and mutations directly in index.js, removing unnecessary imports.
- Updated mutations.js to use a consistent naming convention for setting countries.
- Cleaned up state.js to maintain a clear structure for Vuex state management.

package.json

@@ -36,31 +36,29 @@
 		"deploy": "sh deploy.sh"
 	},
 	"dependencies": {
-		"axios": "^0.21.1",
-		"bulma": "^0.9.1",
-		"core-js": "^3.6.5",
-		"vue": "^2.6.11",
-		"vuex": "^3.6.0",
-    "vue-template-compiler": "^2.6.12"
+		"axios": "^1.12.2",
+		"bulma": "^0.9.4",
+		"core-js": "^3.46.0",
+		"vue": "^2.7.16",
+		"vuex": "^3.6.2"
 	},
 	"devDependencies": {
 		"@babel/core": "^7.12.10",
 		"@babel/preset-env": "^7.12.11",
-		"@vue/cli-plugin-babel": "~4.5.0",
-		"@vue/cli-plugin-eslint": "~4.5.0",
+		"@vue/cli-plugin-babel": "^3.12.1",
+		"@vue/cli-plugin-eslint": "^3.12.1",
 		"@vue/cli-service": "~4.5.0",
-		"@vue/test-utils": "^1.1.2",
+		"@vue/test-utils": "^2.4.6",
 		"babel-core": "^7.0.0-bridge.0",
 		"babel-eslint": "^10.1.0",
-		"babel-jest": "^26.6.3",
-		"eslint": "^6.7.2",
+		"babel-jest": "^30.2.0",
+		"eslint": "^7.32.0",
 		"eslint-plugin-jest": "^24.1.3",
-		"eslint-plugin-vue": "^6.2.2",
-		"jest": "^26.6",
+		"eslint-plugin-vue": "^7.20.0",
+		"jest": "^30.2.0",
 		"jest-serializer-vue": "^2.0.2",
 		"regenerator-runtime": "^0.13.7",
-		"vue-jest": "^3.0.7",
-		"vue-template-compiler": "^2.6.11"
+		"vue-template-compiler": "^2.7.16"
 	},
 	"eslintConfig": {
 		"root": true,