Add library file caching to h5p

Before installing the patch We emulate remote file storage, adding a delay when retrieving the content of the files: 1. Download the attached file fakeremotefilestorage.diff in your Moodle root folder. 2. Apply the patch: patch -p1 < fakeremotefilestorage. diff 3. Log in as admin. 4. Go to 'Content bank' (in the drawer for Boost theme, in Navigation block > Site pages for Classic theme). 5. Open DevTools by pressing Control+Shift+J or Command+Option+J (Mac). 6. Click on the Network tab. 7. Type embed.php? into the Filter text box. 8. Click on 'Upload' button. 9. Upload attached interactivevideo.h5p file and 'Save changes'. 10. Wait until the page displays the H5P content. 11. Write down the load time of the embed.php request. 12. Click on the Close button. 13. Repeat steps 8-11: the timing should be similar. After installing the patch and upgrading the site 14. Go to 'Content bank' (in the drawer for Boost theme, in Navigation block > Site pages for Classic theme). 15. Repeat steps 8-11: the cache is filled with the H5P library files. 16. Repeat steps 8-11: H5P content display should be faster. 17. Confirm that the load time in step 16 is significantly less than the previous ones.