Typescript: replace custom types for OpenUI5 classes in "base" with OpenUI5 type definitions

[ilhan007]

Feature Request Description

In "base" package we require several OpenUI5 Core classes via window.sap.ui.require as part of the OpenUI5 integration scenarios and use custom types to describe the classes

Proposed Solution

Make use of the OpenUI5 type definitions (provided by "@types/openui5") as done for the "localization" package.

Priority

• [ ] Low
• [x] Medium
• [ ] High
• [ ] Very High

A clear and concise description of the impact/urgency of the required feature.

Stakeholder Info (if applicable)

• Organization: internal
• Business impact: {...}

[nnaydenow]

We are waiting following types to appear in OpenUI5:

sap/ui/core/Configuration.js

• definition getCalendarType function
• definition of getThemeRoot function

sap/ui/core/LocaleData.js

• definition of getInstance function

Once they're added we can replace custom types.