Support adding multiple tags in `bicep publish`

**Is your feature request related to a problem? Please describe.**
There are some cases where users might want to add multiple tags to a module in the registry during publish.

**Describe the solution you'd like**
Add the possibility to add multiple tags with `bicep publish`

Something like:
```
bicep publish file.bicep --target br:example.azurecr.io/hello/world:v1.1:latest`

or

bicep publish file.bicep --target br:example.azurecr.io/hello/world:v1.1 --additional-tags latest`
```

Start at the bicep publish command and its --target argument handling. Compare the proposed repeated-tag and --additional-tags forms, then verify that publishing a module applies multiple registry tags and that the chosen command syntax is covered by the relevant tests.

Written by the indexing model from the issue text.