Passing the ApiBaseline to compare as a paramter when possible instead of using static singelton

[laeubi]

Currently a lot of place depend on calling IApiBaselineManager.getWorkspaceBaseline() what has some pitfalls, e.g. when the baseline changes during an operation.

Also we currently only support one baseline while different projects in a workspace might want to use a different one.

To prepare for a change we should identify places where we gather the workspace baseline and use argument passing whenever possible where we do not break backward compatibility (e.g. because we need to change public interfaces) and pull up IApiBaselineManager.getWorkspaceBaseline() calls as much as possible.