[DBClientTest] Change the file name.

DBClientTest ->
DBTablesTest.

This patch only changes the file name.
[DBTablesTest] Take in DB setup functions from Helpers.

The setup function of Database uses the data defined in
DBTablesTest. So it's natural to be in the same file.
[TBTablesTest] Add an initialization method: setupTestDB().

Recently, the way to setup DBs for a test has been increaesed
and complicated. Especially, current tests have  to include lines to
initializes DBs.

This patch is the first step to solve the problem.
Hereafter all tests using DBs basically call setupTestDB() in
cut_setup(). Then they call loadTestDBxxxx() if needed.
[testArmZabbixAPI] Use a new fashion of the test DB setup.
[testDBTablesAction] Use a new fashion of the test DB setup.
[testDBTablesMonitoring] Use a new fashion of the test DB setup.
[testDBTablesMonitoring] Remove unnecessary lines.
[testDBTablesMonitoring] Remove unnecessary lines.
[testDBTablesMonitoring] Use a new fashion of the test DB setup.
[testHapZabbixAPI] Use a new fashion of the test DB setup.
[testIncidentSenderManager] Use a new fashion of the test DB setup.
[testIncidentSenderRedmine] Use a new fashion of the test DB setup.
[DBTablesTest] Hide deleteDBClientHatoholDB() that shouldn't be called from anywhere.
[testActionManager] Replace deprecated functions.

setup ->
cut_setup

teardown ->
cut_teardown
[testActionManager] Remove unnecessary assertions.

getenv() doesn't set errono according to the man.
[testActionManager] Reset errno before the test to avoid positive false.
[testActionManager] Use a new fashion of the test DB setup.
[testDBTablesConfig] Use a new fashion of the test DB setup.
[testDBTablesHost] Use a new fashion of the test DB setup.
[testDataQueryContext] Use a new fashion of the test DB setup.