Allow to disable renaming downloaded files with "(n)" when that filename already exists

Behavior: When downloading a file into a folder which already have a file with the same name, a `(n)` suffix is added to the filename.

I want to be in control of that.
Moreover 99% of the time this is wrong for me – and I guess especially for developers who need to repeat the same file download multiple times.

Same as #128653.

Overwrite option would definitely be good but you should also try renaming the files with names in kanji.