Merge 1.0 into master

 - Verify the creation of ByteString variable using
   UA_Server_DataSetReader_addTargetVariables

Change-Id: Ia9acb07b5eca73708df9bc17b7f6bb5aa81e8790
Signed-off-by: Thangavaila Kalyani Thangaraja <thangavaila.k@kalycito.com>

tutorial_pubsub_subscribe.c

 - Copy data of specified length using UA_snprintf statement
   in ua_pubsub.c
 - Change UA_LOG_WARNING to UA_LOG_ERROR when variable node
   addition fails in UA_Server_DataSetReader_addTargetVariables

Change-Id: I6c5947f7330d24a31d5d00d186015d6fc9f5f720
Signed-off-by: Thangavaila Kalyani Thangaraja <thangavaila.k@kalycito.com>

fixes #3048

The container can be built with:
`docker build -t open62541 . && docker run -p 4840:4840 open62541`

fixes #3001

Add badge for azure pipeline

This gives a warn if a function is used that can potentially lead to a
deadlock.

1. generateChildNodeId: Used to define NodeIds for automatically generated nodes during recursive node instantiation
2. createOptionalChild: Used to define whether an optional child should be created during recursive node instantiation

1. generateChildNodeId: Used to define NodeIds for automatically generated nodes during recursive node instantiation
2. createOptionalChild: Used to define whether an optional child should be created during recursive node instantiation