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/urfave/cli/v2/errors.go

@@ -17,11 +17,10 @@ var ErrWriter io.Writer = os.Stderr
 // MultiError is an error that wraps multiple errors.
 type MultiError interface {
 	error
-	// Errors returns a copy of the errors slice
 	Errors() []error
 }
 
-// NewMultiError creates a new MultiError. Pass in one or more errors.
+// newMultiError creates a new MultiError. Pass in one or more errors.
 func newMultiError(err ...error) MultiError {
 	ret := multiError(err)
 	return &ret
@@ -48,6 +47,28 @@ func (m *multiError) Errors() []error {
 	return errs
 }
 
+type requiredFlagsErr interface {
+	error
+	getMissingFlags() []string
+}
+
+type errRequiredFlags struct {
+	missingFlags []string
+}
+
+func (e *errRequiredFlags) Error() string {
+	numberOfMissingFlags := len(e.missingFlags)
+	if numberOfMissingFlags == 1 {
+		return fmt.Sprintf("Required flag %q not set", e.missingFlags[0])
+	}
+	joinedMissingFlags := strings.Join(e.missingFlags, ", ")
+	return fmt.Sprintf("Required flags %q not set", joinedMissingFlags)
+}
+
+func (e *errRequiredFlags) getMissingFlags() []string {
+	return e.missingFlags
+}
+
 // ErrorFormatter is the interface that will suitably format the error output
 type ErrorFormatter interface {
 	Format(s fmt.State, verb rune)
@@ -65,13 +86,20 @@ type exitError struct {
 	message  interface{}
 }
 
-// NewExitError makes a new *exitError
+// NewExitError calls Exit to create a new ExitCoder.
+//
+// Deprecated: This function is a duplicate of Exit and will eventually be removed.
 func NewExitError(message interface{}, exitCode int) ExitCoder {
 	return Exit(message, exitCode)
 }
 
-// Exit wraps a message and exit code into an ExitCoder suitable for handling by
-// HandleExitCoder
+// Exit wraps a message and exit code into an error, which by default is
+// handled with a call to os.Exit during default error handling.
+//
+// This is the simplest way to trigger a non-zero exit code for an App without
+// having to call os.Exit manually. During testing, this behavior can be avoided
+// by overiding the ExitErrHandler function on an App or the package-global
+// OsExiter function.
 func Exit(message interface{}, exitCode int) ExitCoder {
 	return &exitError{
 		message:  message,
@@ -87,10 +115,14 @@ func (ee *exitError) ExitCode() int {
 	return ee.exitCode
 }
 
-// HandleExitCoder checks if the error fulfills the ExitCoder interface, and if
-// so prints the error to stderr (if it is non-empty) and calls OsExiter with the
-// given exit code.  If the given error is a MultiError, then this func is
-// called on all members of the Errors slice and calls OsExiter with the last exit code.
+// HandleExitCoder handles errors implementing ExitCoder by printing their
+// message and calling OsExiter with the given exit code.
+//
+// If the given error instead implements MultiError, each error will be checked
+// for the ExitCoder interface, and OsExiter will be called with the last exit
+// code found, or exit code 1 if no ExitCoder is found.
+//
+// This function is the default error-handling behavior for an App.
 func HandleExitCoder(err error) {
 	if err == nil {
 		return