res_config_odbc: Use dynamically sized buffers to store row data so values do not get truncated.

ASTERISK-23582 #close
ASTERISk-23582 #comment Reported by: Walter Doekes

Review: https://reviewboard.asterisk.org/r/3557/
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Merged revisions 414693 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 414694 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 414695 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@414696 65c4cc65-6c06-0410-ace0-fbb531ad65f3