fix(ls): point to parent of ref target in definition service

[glowcloud]

Changes definition service to point to parent element of reference target element, instead of reference target element.

Before:

components:
  schemas:
    Test1:
       type: string
    Test2:
      $ref: "#/components/schemas/Test1" # definition service points to `type:string` line

After:

components:
  schemas:
    Test1:
       type: string
    Test2:
      $ref: "#/components/schemas/Test1" # definition service points to `Test1:` line