chore(database): enhance error handling (#10279)

This PR enhances error handling in the database package by introducing
custom error types that wrap dialect-specific errors, providing better
abstraction and context for error handling across the application.

* Introduces standardized custom error types for common database errors
(no rows found, integrity violations, etc.)
* Wraps all PostgreSQL-specific errors at the dialect layer to provide
consistent error handling

# Which Problems Are Solved

The database package didn't wrap the errors from dialect specifc
packages.

# How the Problems Are Solved

Custom errors were added which wrap the dialect specifc errors.

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

backend/v3/storage/database/dialect/postgres/rows.go

@@ -10,10 +10,29 @@ import (
 var (
 	_ database.Rows            = (*Rows)(nil)
 	_ database.CollectableRows = (*Rows)(nil)
+	_ database.Row             = (*Row)(nil)
 )
 
+type Row struct{ pgx.Row }
+
+// Scan implements [database.Row].
+// Subtle: this method shadows the method ([pgx.Row]).Scan of Row.Row.
+func (r *Row) Scan(dest ...any) error {
+	return wrapError(r.Row.Scan(dest...))
+}
+
 type Rows struct{ pgx.Rows }
 
+// Err implements [database.Rows].
+// Subtle: this method shadows the method ([pgx.Rows]).Err of Rows.Rows.
+func (r *Rows) Err() error {
+	return wrapError(r.Rows.Err())
+}
+
+func (r *Rows) Scan(dest ...any) error {
+	return wrapError(r.Rows.Scan(dest...))
+}
+
 // Collect implements [database.CollectableRows].
 // See [this page](https://github.com/georgysavva/scany/blob/master/dbscan/doc.go#L8) for additional details.
 func (r *Rows) Collect(dest any) (err error) {
@@ -23,7 +42,7 @@ func (r *Rows) Collect(dest any) (err error) {
 			err = closeErr
 		}
 	}()
-	return pgxscan.ScanAll(dest, r.Rows)
+	return wrapError(pgxscan.ScanAll(dest, r.Rows))
 }
 
 // CollectFirst implements [database.CollectableRows].
@@ -35,7 +54,7 @@ func (r *Rows) CollectFirst(dest any) (err error) {
 			err = closeErr
 		}
 	}()
-	return pgxscan.ScanRow(dest, r.Rows)
+	return wrapError(pgxscan.ScanRow(dest, r.Rows))
 }
 
 // CollectExactlyOneRow implements [database.CollectableRows].
@@ -47,7 +66,7 @@ func (r *Rows) CollectExactlyOneRow(dest any) (err error) {
 			err = closeErr
 		}
 	}()
-	return pgxscan.ScanOne(dest, r.Rows)
+	return wrapError(pgxscan.ScanOne(dest, r.Rows))
 }
 
 // Close implements [database.Rows].