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/mitchellh/mapstructure/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.4.3
+
+* Fix cases where `json.Number` didn't decode properly [GH-261]
+
 ## 1.4.2
 
 * Custom name matchers to support any sort of casing, formatting, etc. for

vendor/github.com/mitchellh/mapstructure/mapstructure.go

@@ -684,16 +684,12 @@ func (d *Decoder) decodeUint(name string, data interface{}, val reflect.Value) e
 		}
 	case dataType.PkgPath() == "encoding/json" && dataType.Name() == "Number":
 		jn := data.(json.Number)
-		i, err := jn.Int64()
+		i, err := strconv.ParseUint(string(jn), 0, 64)
 		if err != nil {
 			return fmt.Errorf(
 				"error decoding json.Number into %s: %s", name, err)
 		}
-		if i < 0 && !d.config.WeaklyTypedInput {
-			return fmt.Errorf("cannot parse '%s', %d overflows uint",
-				name, i)
-		}
-		val.SetUint(uint64(i))
+		val.SetUint(i)
 	default:
 		return fmt.Errorf(
 			"'%s' expected type '%s', got unconvertible type '%s', value: '%v'",