Rewrite Readme. Review and improve code examples

[NickVolynkin]

readme: Explain example purpose and restructure

• Explain the localization mechanism in more detail.
• Add screenshots of localized Report Designer and Report viewer.
• Add links to documentation.
• Give an overview of files with relevant code.

Readme preview: https://github.com/NickVolynkin/vcl-reports-localize/blob/volynkin-restructure-readme/README.md

delphi/cpp-builder: Focus the example on DevExpress Reports localization

• Add an empty example report to ensure both dialogs can load.
• Switch languages using TcxRadioButtons.
  TcxRadioButtons better represent application state than simple buttons.
• Use the German localization language when application starts.
  Check the "German" radiobutton to reflect the default localization.
• Group "Display Report" buttons into a labeled group, change captions.
  Move focus to "Display Report Designer" button when application starts.
• Forbid to resize the application form.
• Give the application a relevant title.
• Use a DevExpress application icon.
• Remove the Data Grid table.
  In this example, data structure is not in the focus of demonstration.
  Data Grid table draws attention from the localization examples.
• Rename several interface components and code members according to
  DevExpress style.
• Comment significant actions in the code example.
• delphi: Apply the DevExpress Skin Controller