Fix issue 806 - Missing y-label in network report chart

[RyanNgoDev]

Description

• Added y-label for prefix tags chart
• Fixed chart layout not updated when adding y-label or other properties
• This fix covers similar cases using y-label (which were not showed). Eg: ''Upstream'' ASes chart below
  

Motivation and Context

Fix Issue #806

How Has This Been Tested?

Tested on local machine

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[dpgiakatos]

Thanks!