Rename downloaded pages if the file name exists

[HT-7]

Is your feature request related to a problem? Please describe.
While I like the feature which allows downloading pages when sending URLs to it, it has one problem:

When downloading the page a second time (i.e. because it has updated), then the existing HTML file will be overwritten.

Overwriting by default is a poor behaviour (not programmer's fault but default in UNIX, as far as I know, thus only a result of neglect), which has caused me to lose my backed up log by 3C Battery Monitor Widget (file name: bmw_history.txt).

Describe the solution you'd like
If the file name exists, rename the new files to example(1).html, example(2).html , and continuing.

Describe alternatives you've considered
Google Chrome for Android allows MHTML downloading, but not in Incognito mode.

Mozilla Firefox for Android allows PDF downloading, but PDF is not quite a website format (better than nothing, obviously).

[HT-7]

Side note: Yes, I could indeed rename the existing HTML file in advance, but doing that every single time is inconvenient. And one could forget to do it.

[EmmanuelMess]

We should add a dialog to put in a new name.

[TranceLove]

I wonder if there's a library handle all this naming stuff?

[VishalNehra]

Edit: maybe use the same dialog which we use when copying existing file. We already have it to handle Overwrite / skip actions. We can add one more action to Rename it to (1) or (2) instead. It'll help in copy / cut scenario as well.
Let me pick this up.
@TranceLove i don't think we need a library for this. Should be straightforward.

[VishalNehra]

Possible duplicate #1589

[VishalNehra]

Duplicate #1366
Related #721
Will pick this and close all the issues.

[EmmanuelMess]

v3.5 milestone? It should be at least 3.6 this is not a bug.