[modbus] fix defaults for tcp and serial things and some other minor cleanup

[ssalonen]

Small improvements and fixes:

• Resolve modbus itests to remove dependency to apache commons (was removed in [modbus] Replace apache commons lang usage with plain java #10002)
• AbstractModbusEndpointThingHandler poolConfiguration is never null in practice with properly configured tcp/serial endpoints. Therefore marking with @NonNullByDefault({})
• One of the itests did used mocked ModbusManager, leading to no-op test. Fixed now (test still passes)

More significant finding:

• Now utilizing the defaults documented for tcp and serial configurations. Presumably wrong values were used if one did not explicitly specify the values, e.g. slave id of zero was used instead of 1, or default delay of zero was used between transactions (timeBetweenTransactionsMillis) instead something more robust

Signed-off-by: Sami Salonen ssalonen@gmail.com

[ssalonen]

Fyi @Rossko57 on the incorrect defaults

[ssalonen]

Regression test added in fbdeb73

I can confirm that the test indeed fails with the main branch:

git checkout origin/main
git checkout -b roska
git cherry-pick fbdeb739acb6421a940b552f90999d5fd21f762c
mvn install -DwithResolver -pl itests/org.openhab.binding.modbus.tests

result:

TEST org.openhab.binding.modbus.tests.ModbusTcpThingHandlerTest#testTwoDifferentEndpointWithDifferentParameters() <<< ERROR: expected: <EndpointPoolConfiguration [interTransactionDelayMillis=1, interConnectDelayMillis=0, connectMaxTries=1, reconnectAfterMillis=0, connectTimeoutMillis=10000]> but was: <EndpointPoolConfiguration [interTransactionDelayMillis=60, interConnectDelayMillis=0, connectMaxTries=3, reconnectAfterMillis=0, connectTimeoutMillis=0]>
org.opentest4j.AssertionFailedError: expected: <EndpointPoolConfiguration [interTransactionDelayMillis=1, interConnectDelayMillis=0, connectMaxTries=1, reconnectAfterMillis=0, connectTimeoutMillis=10000]> but was: <EndpointPoolConfiguration [interTransactionDelayMillis=60, interConnectDelayMillis=0, connectMaxTries=3, reconnectAfterMillis=0, connectTimeoutMillis=0]>
	at org.junit.jupiter.api.AssertionUtils.fail(AssertionUtils.java:55)
	at org.junit.jupiter.api.AssertionUtils.failNotEqual(AssertionUtils.java:62)
	at org.junit.jupiter.api.AssertEquals.assertEquals(AssertEquals.java:182)
	at org.junit.jupiter.api.AssertEquals.assertEquals(AssertEquals.java:177)
	at org.junit.jupiter.api.Assertions.assertEquals(Assertions.java:1124)
	at org.openhab.binding.modbus.tests.ModbusTcpThingHandlerTest.testTwoDifferentEndpointWithDifferentParameters(ModbusTcpThingHandlerTest.java:108)

[Hilbrand]

LGTM