Installer cannot proceed unless dvndb is dropped

What steps does it take to reproduce the issue?
Reinstall Dataverse in the terminal without first dropping the dvndb database, which was created through the initial installation.

• When does this issue occur?
  During installer phase i.e. if your Dataverse installer failed somewhere in the process in your first try but it got past creating the database. Then when having fixed the issues and running the installer again, this issue will happen.

• What happens?
  The terminal writes, that it cannot proceed because an existing database is found.

Then you have to stop installation and manually perform the following to remove the dvndb database:

psql -U postgres
DROP DATABASE dvndb;
\q

After this you can try to reinstall Dataverse,

• To whom does it occur (all users, curators, superusers)?
  All system administrators.

• What did you expect to happen?
  The installer should prompt the user to accept one of following choices: Reuse the existing database, drop existing database or cancel installation.

Which version of Dataverse are you using?
5.14

Postface
Thx to @DaftPug for work on this one.

Start by tracing the Dataverse installer phase that detects the existing dvndb database and reviewing how the PostgreSQL setup is handled. Done means a reinstall can offer choices to reuse the database, drop it, or cancel, rather than requiring manual psql commands.