Change JsonEncodedType.impl to TEXT

All JSON fields in Ironic currently use the TEXT type, not VARCHAR.
However, the `impl` attribute on JSON types is set to VARCHAR.
This change sets `impl` to TEXT for consistency.

Change-Id: I9ba2fb21ef60ec4c4a8e0f7fe3af97aa3679cc22
Imported Translations from Transifex

Change-Id: I855a8490df894c85bf6a3010e111cbfd341dd952
Merge "Change JsonEncodedType.impl to TEXT"
Merge "Imported Translations from Transifex"