Add MQ_QMGR_PRIMARY_LOGFILES, MQ_QMGR_SECONDARY_LOGFILES env variables for configuring logfiles

[mrboros]

This pull request is about to introduce two new environment variables:

• MQ_QMGR_PRIMARY_LOGFILES - this is to configure the total count of primary logfiles used by the queue manager
• MQ_QMGR_SECONDARY_LOGFILES - this is to configure the total count of secondary logfiles used by the queue manager

With these two variables, you can configure the amount of log files to be created when initializing the container. The behaviour of these new variables (checks, scope, tests) are the same as the MQ_QMGR_LOG_FILE_PAGES parameter. A sample invocation is demonstrated below:

docker run  \
--env LICENSE=accept \
--env MQ_QMGR_NAME=QM1 \
--env MQ_QMGR_PRIMARY_LOGFILES=64 \
--env MQ_QMGR_SECONDARY_LOGFILES=32 \
--publish 1414:1414 \
--publish 9443:9443 \
--detach \
icr.io/ibm-messaging/mq

The reason behind this pull request is that the default values (primary: 3, secondary: 2) are often not ideal for a dev or prod environment.

The accompanying tests (unit and docker, similar to the LogFilePages ones) are also included in the pull request.