[server][DBAgent] Prepre to clean up the update code.
[server][DBAgent] Make the structure simple.
[server][DBAgent] Define a new version of makeUpdateStatement (Note: this hasn't been used yet).
[server][DBAgent] Define new versions of update (Note: this hasn't been used yet).
[server][testItemTable] Add a missing license header.
[server][DBAgent] Add a constructor of TableProfile.
[server][testDBAgent] add a new test: test_createTableProfileWithIvalidNumIndexes().
[server][DBAgent] Rename a structure.

This structure is not only for the update operation.
It can be used more general.

UpdateRow ->
RowElement
[server][testDBAgent] add a new test: test_createUpdateArg().
[server][testDBAgent] Clean up.
[server][testDBAgent] add a new test: test_updateArgAddInt().
[server][testDBAgent] add a new test: test_updateArgAddUint64().
[server][testDBAgent] add a new test: test_updateArgAddDouble().
[server][testDBAgent] add a new test: test_updateArgAddString().
[server][testDBAgent] add an assertion.
[server][DBClientUser] Define tableProfileUsers.
[server][DBClient] Add a TODO comment.
[server][DBClient] Add a new version of update() with DBAgent::UpdateArg.
[server][DBClientUser] Use a new version of update() to be simple.
[server][DBClientUser] Use a new version of update() to be simple.