Related to ##50954. Happens since we are handling multiple units in durations.

### Steps to reproduce

1. Go to a work package

2. Click work field

3. In the popover, enter "Hello world" as work value

4. Click on "Save"


### What is the buggy behavior?

* The value is accepted, and "0h" is displayed


### What is the expected behavior?

1. It should display an Begin of the insertioninline error:End of the insertion Begin of the deletion error likeEnd of the deletion "is not a valid duration"


### Screenshots and other files

Screen from previous version (14.1.2)

<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/105638/content">

Current version (future 14.2)

<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/105639/content">

### Environment information

**OpenProject installation type**

* [x] Hosted cloud edition
* [ ] Packaged installation
* What distribution?

* [ ] Docker All-in-one container
* [ ] Docker-compose installation
* [ ] Other (please specify)

**OpenProject version**

Future 14.2

**Browser**

* [x] Chrome
* [x] Firefox
* [ ] Safari
* [ ] Mobile Safari
* [ ] Other (please specify)