Web UI does not check if the provided report name exists

[PiotrAniola82]

Describe the bug
Web UI does not check if the provided report name exists

To Reproduce
Steps to reproduce the behavior:

1. Go to http://127.0.0.1:5000
2. Create a report with the name 'test'
3. Later, repeat the steps also using the word 'test' as the name

Expected behavior
The program should not allow to re-use a report name, or
The program should ask you if you want to overwrite the existing report, or
The program should append an ID or sequential number to the name to keep it unique, or, preferably
We should not use names at all.

Actual behaviour
Your old report is silently overwitten, but, on the main page http://127.0.0.1:5000 the report generation time still refers to the first run, instead of the second, which is what it really is.