Add configurable log levels for core engine

[chris1984]

Add parameters to configure logging levels for insights.core.dr, insights_messaging, insights_kafka_service, and root loggers. Defaults preserve existing behavior (ERROR/INFO).

Parameters are exposed in the main iop class for foreman-installer integration with core_engine_ prefix.

Add tests to verify the config secret contains correct log level values for both default and custom configurations. Also test that log level parameters are properly passed through from the main iop class to iop::core_engine.

Output when set to debug:

Feb  2 12:24:09 ip-10-0-168-10 iop-core-engine[177812]: DEBUG:insights.core.dr:telemetry.rules.plugins.networking.network_vlan_i40e_driver_offloading_issue.check_bond_master_slave_config missing requirements All: ['telemetry.rules.plugins.networking.bonding.check_bond_master_slave_conn'] Any:
Feb  2 12:24:09 ip-10-0-168-10 iop-core-engine[177812]: DEBUG:insights.core.dr:telemetry.rules.plugins.aws.aws_cloud_init_support_for_imdsv2.broken_cloud_init_pkg missing requirements All: ['telemetry.rules.plugins.aws.aws_cloud_init_support_for_imdsv2.rhel_main_repos'] Any:
Feb  2 12:24:09 ip-10-0-168-10 iop-core-engine[177812]: DEBUG:insights.core.dr:telemetry.rules.plugins.osp.neutron_ovs_vswitchd_too_small_mac_table_size.rhosp_controller_node missing requirements All: ['telemetry.rules.plugins.osp.rhosp_version'] Any:
Feb  2 12:24:09 ip-10-0-168-10 iop-core-engine[177812]: DEBUG:insights.core.dr:telemetry.rules.plugins.sap.sap_required_packages.check_req_pkgs missing requirements All: ['telemetry.rules.plugins.sap.sap_required_packages.affected_rhel'] Any:
Feb  2 12:24:09 ip-10-0-168-10 iop-core-engine[177812]: DEBUG:insights.core.dr:insights.specs.Specs.pmlog_summary_pcp_zeroconf missing requirements All: [] Any: ['insights.specs.default.DefaultSpecs.pmlog_summary_pcp_zeroconf']
Feb  2 12:24:09 ip-10-0-168-10 iop-core-engine[177812]: DEBUG:insights.core.dr:telemetry.rules.plugins.sap.sap_required_packages.check_req_min_pkgs missing requirements All: ['telemetry.rules.plugins.sap.sap_required_packages.affected_rhel']

New parameters added to iop::core_engine:

Parameter	Default	Description
$log_level_insights_core_dr	ERROR	Log level for insights.core.dr logger
$log_level_insights_messaging	INFO	Log level for insights_messaging logger
$log_level_insights_kafka_service	INFO	Log level for insights_kafka_service logger
$log_level_root	INFO	Log level for root logger

Valid values: DEBUG, INFO, WARNING, ERROR, CRITICAL

Example usage in Hiera:

  iop::core_engine::log_level_insights_core_dr: 'DEBUG'
  iop::core_engine::log_level_root: 'WARNING'

[chris1984]

@ehelms here is the log level pr I was talking about