Lint checks phase 2 (#1747)

* Log 3 unchecked errors

Rather than ignore errors, log them at
the WARNING log level.

The server has been functioning without these, so assume they are not at
the ERROR level.

* Log errors in concurrency test

If we can't initialize the configuration, treat the test as a failure.

* Undo the errcheck on configurations for now.

* Handle unchecked errors in pkg/manager

* Resolve unchecked errors

* Handle DLNA/DMS unchecked errors

* Handle error checking in concurrency test

Generalize config initialization, so we can initialize a configuration
without writing it to disk.

Use this in the test case, since otherwise the test fails to write.

* Handle the remaining unchecked errors

* Heed gosimple in update test

* Use one-line if-initializer statements

While here, fix a wrong variable capture error.

* testing.T doesn't support %w

use %v instead which is supported.

* Remove unused query builder functions

The Int/String criterion handler functions are now generalized.

Thus, there's no need to keep these functions around anymore.

* Mark filterBuilder.addRecursiveWith nolint

The function is useful in the future and no other refactors are looking
nice.

Keep the function around, but tell the linter to ignore it.

* Remove utils.Btoi

There are no users of this utility function

* Return error on scan failure

If we fail to scan the row when looking for the
unique checksum index, then report the error upwards.

* Fix comments on exported functions

* Fix typos

* Fix startup error

pkg/database/transaction.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	"github.com/jmoiron/sqlx"
+	"github.com/stashapp/stash/pkg/logger"
 )
 
 // WithTxn executes the provided function within a transaction. It rolls back
@@ -17,11 +18,15 @@ func WithTxn(fn func(tx *sqlx.Tx) error) error {
 	defer func() {
 		if p := recover(); p != nil {
 			// a panic occurred, rollback and repanic
-			tx.Rollback()
+			if err := tx.Rollback(); err != nil {
+				logger.Warnf("failure when performing transaction rollback: %v", err)
+			}
 			panic(p)
 		} else if err != nil {
 			// something went wrong, rollback
-			tx.Rollback()
+			if err := tx.Rollback(); err != nil {
+				logger.Warnf("failure when performing transaction rollback: %v", err)
+			}
 		} else {
 			// all good, commit
 			err = tx.Commit()