Refactor and add core data structures to core package rather than strhelper or other

Data-structures to be added / Refactor and add core data structures to core package rather than strhelper or other

• Strings Collection
• String Collection map
• String to String Map
• String to Strings Map
• String HashSet
• Char to StringsCollection map -> CharCollectionMap

Background why needed?

Previously common data structures were added to the strhelper package, however, it seems like those structures should be available in the core or root level than the specific package.

Problem Encounter

We want the core package to be the root of all packages and strhelper is also a core package, such core packages like strhelper, pathhelper should not depend on each other but all depend on the core package, and in specific cases pathhelper requires data structures which currently resides in strhelper.

Solution

We need to include the core data structures to reside in the core rather than any other package.