Source-string suggestions without direct editing

### Describe the issue

I want to leave suggestions for source strings.

If I understand it correctly the "read-only" flag is on by default and lifted when direct editing is turned on.
(Suggestions for source strings work for projects that also allow direct editing of source strings.)

In any event it isn't possible to leave suggestions for strings by default, (with "suggestions" turned on),
top of https://hosted.weblate.org/settings/remmina/remmina/#translation
and it isn't possible to remove the "read-only" flag. in the settings for any strings.

Says "read-only" is inherrited from project/component — English, but that is what I am trying to edit, and it isn't bulk-added…

### I already tried

- [X] I've read and searched [the documentation](https://docs.weblate.org/).
- [X] I've searched for similar issues in this repository.

### Steps to reproduce the behavior

1. add project.
2. try to add suggestion for any source string.

### Expected behavior

Suggestions should be allowed by default (as now), for all projects.

### Screenshots


### Exception traceback

_No response_

### How do you run Weblate?

weblate.org service

### Weblate versions

_No response_

### Weblate deploy checks

_No response_

### Additional context

I didn't try to turn on suggestion voting, which just sits at 0 votes.
Useful for people that don't have GitHub accounts, or don't want to leave suggestions in comments.

Would be a nice use-case for admins to come in and click yes or no to suggestions with direct editing that is only available to them.