Interpolate the log message also for logged exceptions

[ChristophWurst]

According to PSR-3 the log message can have placeholders that are
replaced from the context object. Our logger implementation did that for
all PSR-3 logger methods. The only exception was our custom logException.

Since PsrLoggerAdapter calls logException when an exception key is
present in the context object, log messages were no longer interpolated.

Tested with the following snippet

		try {
			throw new \InvalidArgumentException('henlo');
		} catch (\Throwable $e) {
			$logger->debug('oh {no}', [
				'no' => 'no',
				'exception' => $e,
			]);
		}

On master I get oh {no} in my log. With this patch it's oh no.

[ChristophWurst]

/backport to stable23

[ChristophWurst]

/backport to stable22

[ChristophWurst]

/backport to stable21

[nickvergessen]

Fine by me also with backports, but 20 is EOL

[ChristophWurst]

20 is EOL

TIL!