[DDC-2802] Fix unsupported MySQL index column sizes

[velosipedist]

Extends Index constructor with array $options for any possible index modifications.

For example, Oracle have a very huge list of index tuning options.

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[velosipedist]

For now, i'm rewriting also Table::addIndex() signature.
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[deeky666]

@beberlei I think this is a duplicate of #419 and should be closed, too.

[beberlei]

This will be added in a different manner later and is on our backlog.