FLUT-933401 - [Others] Updated selection behavior in range selector

[sfHariHaraSudhan]

Description

Updated the code snippet for the selection feature in the SfRangeSelector widget in user guide which is suitable for the latest version.

https://help.syncfusion.com/flutter/range-selector/range-controller#selection-with-sfchart

[SyncfusionBuild]

Build Status: INPROGRESS 🔃
Build Location: FLUT-933401-Update-range-selector-in-UG

[SyncfusionBuild]

CI Status: FAILURE ❌
Source Compilation: SUCCESS ✅
Failure Reason: CI Failure with violation
Build Location: FLUT-933401-Update-range-selector-in-UG
Technical Error(s): 0
Spelling Error(s): 0
Image Alt Text Error(s): 0
Image Size Error(s): 0
Image Name Error(s): 0
FT Layout Syntax Error(s): 0
Front matter Error(s): 1
File Path Error(s): 0
CodeSnippet File Path Missing Error(s): 0
Toc Anchor Tags Validation Error(s): 0
MD Tag Validation Error(s): 0

[SyncfusionBuild]

Build Status: INQUEUE 🕒
Build Location: FLUT-933401-Update-range-selector-in-UG

[SyncfusionBuild]

Build Status: INPROGRESS 🔃
Build Location: FLUT-933401-Update-range-selector-in-UG

[SyncfusionBuild]

CI Status: SUCCESS ✅
Source Compilation: SUCCESS ✅
Build Location: FLUT-933401-Update-range-selector-in-UG
Technical Error(s): 0
Spelling Error(s): 0
Image Alt Text Error(s): 0
Image Size Error(s): 0
Image Name Error(s): 0
FT Layout Syntax Error(s): 0
Front matter Error(s): 0
File Path Error(s): 0
CodeSnippet File Path Missing Error(s): 0
Toc Anchor Tags Validation Error(s): 0
MD Tag Validation Error(s): 0

[ghost]

Fine