[TAP] Fix the /tables output: the UCD node was after UType...it should be just before (warning raised by TAPLint)

[TAP,ADQL] Improve and remake a part of the database connection. Missing javadoc has been added when missing in the modified tables.

[TAP] Remove TAPTypes and create a new class to represent a TAP column type: TAPType. + Improve the conversion between VOTable type and TAP type by embedding it in TAPType. + Modify TAPColumn in order to integrate TAPType and that its VotType is just a conversion of a TAPType. {This commit is not compilable.}

[TAP] Rename TAPMetadata.TableIterator into TAPMetadata.TAPTableIterator (it iterates only on the content of a TAPTable object and not on a data table. + Typos