Make sqlite3 db path relative to sqlboiler config file

[kelzenberg]

Having a Go project with a file structure like the following is problematic when using absolute or relative paths as suggested for the sqlite3 database in the sqlboiler config.

| project/
| -- cmd/
| ---- main.go
| -- db/
| ---- sqlite.db
| -- sqlboiler.toml
| -- go.mod

sqlboiler.toml

[sqlite3]
dbname = "db/sqlite.db"

The generation command works fine if ran in root ✅

sqlboiler --config ./sqlboiler.toml --output ./models sqlite3

The path-adjusted Go generate command in main.go will fail ❌

//go:generate sqlboiler --config ../sqlboiler.toml --output ../models sqlite3

The sqlite3 driver is not capable of finding the database sqlite.db as relative paths don't match. The problem can be solved by (optionally) resolving the sqlite3 database' path relative to the sqlboiler config, not the execution context.