Support Go 1.18: Upgrade gqlgen to v0.17.2 (#2443)

* Upgrade gqlgen to v0.17.2

This enables builds on Go 1.18. github.com/vektah/gqlparser is upgraded
to the newest version too.

Getting this to work is a bit of a hazzle. I had to first remove
vendoring from the repository, perform the upgrade and then re-introduce
the vendor directory. I think gqlgens analysis went wrong for some
reason on the upgrade. It would seem a clean-room installation fixed it.

* Bump project to 1.18

* Update all packages, address gqlgenc breaking changes

* Let `go mod tidy` handle the go.mod file

* Upgrade linter to 1.45.2

* Introduce v1.45.2 of the linter

The linter now correctly warns on `strings.Title` because it isn't
unicode-aware. Fix this by using the suggested fix from x/text/cases
to produce unicode-aware strings.

The mapping isn't entirely 1-1 as this new approach has a larger iface:
it spans all of unicode rather than just ASCII. It coincides for ASCII
however, so things should be largely the same.

* Ready ourselves for errchkjson and contextcheck.

* Revert dockerfile golang version changes for now

Co-authored-by: Kermie <kermie@isinthe.house>
Co-authored-by: WithoutPants <53250216+WithoutPants@users.noreply.github.com>

vendor/github.com/99designs/gqlgen/graphql/errcode/codes.go

@@ -4,8 +4,10 @@ import (
 	"github.com/vektah/gqlparser/v2/gqlerror"
 )
 
-const ValidationFailed = "GRAPHQL_VALIDATION_FAILED"
-const ParseFailed = "GRAPHQL_PARSE_FAILED"
+const (
+	ValidationFailed = "GRAPHQL_VALIDATION_FAILED"
+	ParseFailed      = "GRAPHQL_PARSE_FAILED"
+)
 
 type ErrorKind int