This commit addresses issues around vendoring the 3rd party GraphQL
parser library, `vektah/gqlparser`, which is used by our GraphQL builtins.
By directly depending on the library, we accidentally forced all of our
library users to have to match `gqlparser` versions, which could cause
problems if they wanted to use downstream GraphQL libraries.
To fix this version clash problem, this PR internalizes `vektah/gqlparser`
v2.4.8 into the `internal/gqlparser` package (we can update to v2.5.0
later). Scripts are included to automate some of the internalizing
process if we wish to update the library in the future.
Fixes: #5065
Signed-off-by: Philip Conrad <philipaconrad@gmail.com>