[Feature Request] word wrap improvement: make the current line visible after word wrap state change

[25minutes]

After I trun on word wrap, the current line often moves out of the display area. I have to scroll the document to find it again. It would be convenient if it can automatilly "goto" the current line after word wrap state change.

[zufuliu]

Related to #692, can be implemented for small file when parallel wrap block is implemented.