Decouples Cache and Download behaviour

[akabhirav]

Decoupling Cache and Download behaviour

Separating cache directory from Download directory

Tachidesk's caching and download logic are tightly coupled. This includes the cache directory being the same as download directory. Ideally the directory for files meant to be temporarily stored as cache should be the operating system's temp directory. The first change deals with changing the cache directory to the OS' temp directory

Implementing a new Downloader logic

Now that cached files are stored in another place, the downloader relying on cache logic to store the page(image) files no longer works. To fix this we need to make the downloader self-reliant which only asks the ImageRespone to be in image and then stores the file to the download folder on it's own

Technicals

All of this introduces a few new changes in the server:

1. Introduced DownloadedFilesProvider as an abstract class which sets up the struture for a provider that is responsible for handling downloaded files i.e. getting, putting and deleting pages.
2. Introduced FileProvider as the default provider implementing DownloadedFilesProvider that implements the default behaviour of saving each page as a separate image in the chapter folder inside downloads directory.
3. Introduced ChapterDownloadHelper object that works as a DownloadedFilesProvider factory which generates the appropriate provider object. This abstracts the complexity that each provider must implement to store it's own logic for the above mentioned tasks.

[akabhirav]

going to change this to download since we don't need a single put image here, we can just move the entire downlod logic here. Also, building an ArchiveProvider is proving difficult since appending to zip is not working for some reason

[akabhirav]

Made this change in the latest commit

[akabhirav]

@Syer10 made the changes you've requested till now