Update Directives and Modules naming consistency

[kdinev]

Updating initial issue description

Description

Directive and Module names should be consisent for, we follow the official angular styleguide and directives like IgxInputClass should be renamed to IgxInputDirective, same applies to the exported modules.

• Review all names of Directives and Modules and make them consistent to the naming styleguide
• Change the structure (if needed):
• Move standalone Directives under src/directives/'directiveNameFolder' folder
• Directives related to components to be left in parent folder again under directives/ folder
• Update all related topics, reademe.md files and wiki pages based on the structural and naming changes
• Update all related samples and docfx content
  
• Add codelyzer
  Note: The exported class for the IgxInput naming is inconsistent with IgxLabelModule for example.

Result

Naming is inconsistent.

Expected result

Naming is consistent