Crash on new context when expanding search service options

[MV88]

Description

This issue has been generated from here

How to reproduce

• create a new context, for example this one https://mapstore.geosolutionsgroup.com/mapstore/#/context/allplugins
• try to enter search service config options
  

Expected Result

the services panel opens

Current Result

crash

• Not browser related

Browser info

(use this site: https://www.whatsmybrowser.org/ for non expert users)

Browser Affected	Version
Internet Explorer
Edge
Chrome
Firefox
Safari

Other useful information

[dsuren1]

Investigation:
The issue happens when adding loading a context with SearchServicesConfig plugin added

However, it doesn't happen when navigation from context manager because upon mount a reset control is dispatched which adds some default state to searchconfig reducer. But loading search plugin SearchServicesConfig enabled context by refreshing the page (while in the context) will result in a null state. And trying to read a property from a null state results in page crash exception.

Fix should be simple as checking null and returning a default here (best done on all props), should resolve it

[tdipisa]

@dsuren1 thank you, you can proceed with the fix.