fi: Fixed several typos, word orders, left/right distinction

There were some typos and word order issues in the Finnish TTS strings, probably resulting from a machine translation.
Also changed all instances of "vasemmalle" to "vasempaan" to fit with the Finnish military custom on differentiating between left/right in noisy environments. Grammatically these are interchangeable in this context, but it is much easier to hear the difference this way.