Merge Request Filters

### Describe your use-case which is not covered by existing documentation.

We have some gitlab repo's that are a fork of other repo's,
when we try to perform **_Scan Gitlab Project Now_** discovery, we can see at the log the following line:
```
Ignoring merge requests as project is a mirror...
```

for other repo's, which are not connected to any other repo, when we perform **_Scan Gitlab Project Now_** we can see at the log the following line:
```
Unable to detect if it is a mirror or not still fetching MRs anyway...
```

what are the criterions for these filters?
what's causing the plugin to assume that the repo is a mirror / not ?

### Reference any relevant documentation, other materials or issues/pull requests that can be used for inspiration.

_No response_

### Are you interested in contributing to the documentation?

_No response_