[Android] Add a "Select all" Feature for creating albums

[d3rm1ch1h0]

Is your feature request related to a problem? Please describe.
When i want to make an album on my android device i would love to have the option to select all images in an folder or to select the folder directly to "add all containing fotos to an album.

It should not matter if they are synced or not. in case they are not it would be great if they get uploaded automatically and pushed to the album.

Describe the solution you'd like
Scenario 1: when browsing on the android app. Select Explore/Folder. Long tap on a folder i want be able to add all containing images to an album. Or go into the folder select one image, now i want be able to tap on "select all" to move all to an album

scenario 2: when browsing my local files, i want be able to also select photos which should be added to an album (upload required in the background)

Describe alternatives you've considered
a workaround: you can do that in the web-app, but i do not want to switch to the web version in these cases.