Weekly update #6: More blocks

This update implements some new blocks and various bug fixes

What's new

• New blocks:
  • RGB <-> HSV Conversion
  • Choose Random Choice
  • Swap Vector Channel
  • Convert Type
  • Length
  • Distance
  • Normalize
• Auto scroll to focused block
• Bug fixes:
  • Fix issue when using default variable name
  • Fix array generation when the member is only one
  • Fix gradient dynamic offset not changing
  • Fix vector parameter using Y value for Z
  • Fix error when moving a block to a lower position