Fix Chronostratigraphy Tree name in new disciplines

[alesan99]

Fixes #7823

When creating a new chronostratigraphy tree with the system configuration tool it would be named "Chronostratigraphy_1".
All new disciplines with chrono trees will now always have them named "Chronostratigraphy", since they are the first and only chrono tree in that discipline.

Checklist

• Self-review the PR after opening it to make sure the changes look good and
  self-explanatory (or properly documented)
• Add relevant issue to release milestone
• Add pr to documentation list
• Add automated tests
• Add a reverse migration if a migration is present in the PR

Testing instructions

• Create a new database with a paleo/geo discipline
• The Chronostratigraphy tree should be called "Chronostratigraphy", with no _1 at the end.
• Go to System Configuration
• Create a new paleo/geo discipline
• Create
• Switch to the new collection
• The new Chronostratigraphy tree should be called "Chronostratigraphy", with no _1 at the end.
• Ensure the tree still works correctly. You should still be able to add nodes to it, edit ranks, etc.

[emenslin]

• The new Chronostratigraphy tree should be called "Chronostratigraphy", with no _1 at the end.
• Ensure the tree still works correctly. You should still be able to add nodes to it, edit ranks, etc.

When I created the second discipline 2 chronostrat trees were created, the first one was called "Chronostratigraphy" and the second was "Chronostratigraphy_1".

[alesan99]

@emenslin ah I think I found the issue, it should be fixed now 👍
(The last created chronostrat tree was also being assigned to the new collection)

EDIT:

Actually hold off on testing, changing the base messed some stuff up