[Context Selector] - [Replace Input group with search input]

**Is this a new component or an extension of an existing one?**
What is the existing component, if any? Context Selector

**Describe the feature**
A clear and concise description of the new feature. What is the expected behavior?
The Context selector should use a search input instead of an Input Group

Related core issue: https://github.com/patternfly/patternfly/issues/4786