feat(hub): adding downloadFileToCacheDirWithProgress function

[axel7083]

Description

Related to #1331

To be able to offer a snapshotDownloadWithProgress method, similar to uploadFilesWithProgress the function called by snapshotDownload should also have a WithProgress version.

Splitting the downloadFileToCacheDir function

To avoid doing a big copy paste of the downloadFileToCacheDir function, I needed to split it.

• Created type DownloadFileToCacheDirParams to avoid repeating the params everywhere
• Created function preparePaths to determine the paths based on the params
• Created function ensureDirectories to mkdir the directories
• Created function prepareDownloadFileToCacheDir to handle all the functions above
• Created function downloadAndStoreFile to do the heavy logic of downloading so downloadFileToCacheDir is simpler.

Those functions are exported, so downloadFileToCacheDirWithProgress can nicely use them

Testing

• unit tests have been provided for downloadFileToCacheDirWithProgress