Add common props at _app.js level with caching functionality

[developerKumar]

We should be able to access props at _app.js level, it can be declared as

`
const { fetchMediaDataFromCMS } = require('./service/mediaData.service');

module.exports = () => ({
'/_app': [{ key: 'mediaPosts', data: fetchMediaDataFromCMS }],
});
`

Also, if same function is called by another page let's say

`const { fetchMediaDataFromCMS } = require('./service/mediaData.service');

module.exports = () => ({
'/2021/[id]': [{ key: 'mediaPosts', data: fetchMediaDataFromCMS }],
'/2022/[id]': [{ key: 'mediaPosts', data: fetchMediaDataFromCMS }],
'/_app': [{ key: 'mediaPosts', data: fetchMediaDataFromCMS }],
});
`

then, it should load the data for other pages from cache of the library, should not call the same function to evaluate again and again.