Support cross reference to book part

[rgaiacs]

Bug description

Originally reported at #3218

Quarto supports cross reference to book chapters but does not support to book parts.

Minimal working example.

quarto check output

[✓] Checking Quarto installation......OK
      Version: 1.2.117
      Path: /opt/quarto/bin

[✓] Checking basic markdown render....OK

[✓] Checking Python 3 installation....OK
      Version: 3.9.10 (Conda)
      Path: /home/raniere/mambaforge/bin/python
      Jupyter: (None)

      Jupyter is not available in this Python installation.
      Install with conda install jupyter

[✓] Checking R installation...........OK
      Version: 4.2.1
      Path: /usr/lib/R
      LibPaths:
        - /home/raniere/R/x86_64-pc-linux-gnu-library/4.2
        - /usr/local/lib/R/site-library
        - /usr/lib/R/site-library
        - /usr/lib/R/library
      rmarkdown: 2.16

[✓] Checking Knitr engine render......OK

Checklist

• Please include a minimal, fully reproducible example in a single .qmd file? Please provide the whole file rather than the snippet you believe is causing the issue.
• Please format your issue so it is easier for us to read the bug report.
• Please document the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
• Please document the operating system you're running. If on Linux, please provide the specific distribution.

[baptiste]

I seem to have run into a similar issue with a book I'm writing; references aren't picked up or resolved in the Front and Back matter. I'll try to narrow it down to a minimal example, but I wanted to follow the thread here in case it's the same issue.

[cscheid]

This is a duplicate of #2571.