Improve durations input format

[DuaelFr]

Problem Statement

In time estimates or time spent, we can input duration as a string instead of using the nice circular widget.

1. The most frustrating thing, and I think not that hard to fix, is that we have to separate our time component with a space or it fails.
   For example, 1h 45m works just fine while 1h45m is calculated as 1m
2. As an improvement, we could allow to input 1h45 and guess it was 45 minutes
3. Another improvement would be to allow using floats like 1.5h

❔ Possible Solution

Improve stringToMs to:

1. split on anything but numbers (+ dots, and commas) instead of just spaces.
2. guess the letter if none has been provided for the current part
3. use parseFloat instead of parseInt

⤴️ Describe alternatives you've considered

None

➕ Additional context

Might help solve #3420 and #2983

[github-actions]

Thank you very much for opening up this issue! I am currently a bit overwhelmed by the many requests that arrive each week, so please forgive me, if I fail to respond personally. I am still very likely to at least skim read your request and I'll probably try to fix all (real) bugs if possible and I will likely review every single PR being made (please, give me a heads up if you intent to do so) and I will try to work on popular requests (please upvote via thumbs up on the original issue) whenever possible, but trying to respond to every single issue over the last years has been kind of draining and I need to adjust my approach for this project to remain fun for me and to make any progress with actually coding new stuff. Thanks for your understanding!

[github-actions]

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