feat(cat-gateway): Add stub endpoints to minimally work with norns 1/2

[apskhem]

Description

Added stub endpoints to support norns and made the interface minimally work with norns.
This is the half part of endpoints listed in the ticket's related epic.

Related Issue(s)

Closes #1046

Please confirm the following checks

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream module

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 320/320}$ | ${\color{red}Fail: 0/320}$ |

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 320/320}$ | ${\color{red}Fail: 0/320}$ |

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 320/320}$ | ${\color{red}Fail: 0/320}$ |

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 320/320}$ | ${\color{red}Fail: 0/320}$ |

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 29/29}$ | ${\color{red}Fail: 0/29}$ |

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 331/331}$ | ${\color{red}Fail: 0/331}$ |

[stevenj]

This PR is blocked, as we may not require these endpoints.
Final decision on what to do with these is currently deferred.