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/codegen/object.go

@@ -1,13 +1,13 @@
 package codegen
 
 import (
+	"fmt"
 	"go/types"
 	"strconv"
 	"strings"
 	"unicode"
 
 	"github.com/99designs/gqlgen/codegen/config"
-	"github.com/pkg/errors"
 	"github.com/vektah/gqlparser/v2/ast"
 )
 
@@ -36,7 +36,7 @@ type Object struct {
 func (b *builder) buildObject(typ *ast.Definition) (*Object, error) {
 	dirs, err := b.getDirectives(typ.Directives)
 	if err != nil {
-		return nil, errors.Wrap(err, typ.Name)
+		return nil, fmt.Errorf("%s: %w", typ.Name, err)
 	}
 
 	obj := &Object{
@@ -46,7 +46,7 @@ func (b *builder) buildObject(typ *ast.Definition) (*Object, error) {
 		Stream:             typ == b.Schema.Subscription,
 		Directives:         dirs,
 		ResolverInterface: types.NewNamed(
-			types.NewTypeName(0, b.Config.Exec.Pkg(), typ.Name+"Resolver", nil),
+			types.NewTypeName(0, b.Config.Exec.Pkg(), strings.Title(typ.Name)+"Resolver", nil),
 			nil,
 			nil,
 		),