PDI-7923 - integration test added
PDI-7923 - Formula step requires Number value type when could be used Integer

Added ability to guess Kettle ValueMeta for any Object.
Added ability to Formula step convert calculation result to target output
ValueMeta.
When we achieve formula calculation result as erased Object type we trying
to guess kettle value meta for this type, and convert it to target value
meta.
To reduce perfomance impact we also trying to discover is this conversion
is really necessary. If input value meta is suitable for formula
calculation result we skip conversion and just pass value to next step
signed by output value meta (which was cloned from input value meta).
Merge pull request #488 from prakapenka/PDI-7923

PDI-7923 Formula step requires Number value type when could be used Integer.