Supporting postgres simplifies deployments to environments such as kubernetes. Since sqlite doesn't work well on nfs shares it can be easier for databases to have a dedicated db set up that applications can connect to. Sqlite is easier for most deployments though, so this will default to that if the settings haven't been updated to support it.
This change does the following:
- Separate out SQLite from the DataLayer and adds a Postgres assembly for migrations as well
- Add a configuration setting for a postgres connection string that will be used if it is there, otherwise reverts to the original sqlite string
- Add a copydb command for the cli to bootstrap the postgres db
- A convenience script to update migrations for both dbs at the same time
- Configuration.LibationSettingsAreValid is true if Books property exists and is any non-null, non-empty string.
- If LibationSettingsAreValid is false, Libation will prompt user to set up Libation.
- When the main window is shown, Libation checks if the books directory exists, and if it doesn't, user is notified and prompted to change their setting
- When a user tries to liberate or convert a book, Books directory is validated and user notified if it does not exist.
Automatically determine if filename lengths in the Books directory are limited to 255 UTF-16 characters (NTFS) or 255 UTF-8 bytes (pretty much every other file system) (#1260)
In non-Windows environments, determine if the Books directory supports filenames containing characters which are illegal in Windows environments (<>|:*?). If it doesn't, then ensure those characters are included in the user's ReplacementCharacters settings (#1258).
