[C5] Multi Environment support

[renuka-fernando]

Description:
Allow managing multi instances of API manager from one client interface.

Sub Tasks

• CORS support for environments [C5][environment] CORS support #4697
• Configurations REST API [C5][environment] Configuration API to read configurations from client #4696
• Client side configuration reading [C5][environment] Read environment configurations in Client #4691
• Handle cookies for environments [C5][environment] Handle cookies for environments #4701
• Fix issue in Store Store app not rendering APIs list #4708
• User Interface for environment support [C5][environment] User Interface for environment support #4793
• Single Sign-On Feature for Environment support Multi environment SSO issue product-apim#1957
• Environment Support for Store application [C5][environment] Environment Support for Store with SSO feature #4887
• App specific environment for applications (publisher/store/admin) [C5][environment] Use app specific environment #4888
• Remove uiService query parameter [C5][environment] Enable changing the UI Service with removing uiService query parameter. product-apim#2205