Allow different names for ...rest (#3954)

* Allow different names for ...rest

* Resolves #3945

* This change requires an explicit name for the rest argument in `WholeStreamCommand`,
  which is why there are so many changed files.

* Remove redundant clone

* Add tests

crates/nu-command/src/commands/platform/ansi/gradient.rs

@@ -40,6 +40,7 @@ impl WholeStreamCommand for SubCommand {
                 Some('d'),
             )
             .rest(
+                "rest",
                 SyntaxShape::ColumnPath,
                 "optionally, draw gradients using text from column paths",
             )

crates/nu-command/src/commands/platform/ansi/strip.rs

@@ -15,6 +15,7 @@ impl WholeStreamCommand for SubCommand {
 
     fn signature(&self) -> Signature {
         Signature::build("ansi strip").rest(
+            "rest",
             SyntaxShape::ColumnPath,
             "optionally, remove ansi sequences by column paths",
         )

crates/nu-command/src/commands/platform/exec.rs

@@ -25,6 +25,7 @@ impl WholeStreamCommand for Exec {
         Signature::build("exec")
             .required("command", SyntaxShape::FilePath, "the command to execute")
             .rest(
+                "rest",
                 SyntaxShape::GlobPattern,
                 "any additional arguments for the command",
             )

crates/nu-command/src/commands/platform/kill.rs

@@ -19,7 +19,7 @@ impl WholeStreamCommand for Kill {
                 SyntaxShape::Int,
                 "process id of process that is to be killed",
             )
-            .rest(SyntaxShape::Int, "rest of processes to kill")
+            .rest("rest", SyntaxShape::Int, "rest of processes to kill")
             .switch("force", "forcefully kill the process", Some('f'))
             .switch("quiet", "won't print anything to the console", Some('q'));
 

crates/nu-command/src/commands/platform/run_external.rs

@@ -43,7 +43,7 @@ impl WholeStreamCommand for RunExternalCommand {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).rest(SyntaxShape::Any, "external command arguments")
+        Signature::build(self.name()).rest("rest", SyntaxShape::Any, "external command arguments")
     }
 
     fn usage(&self) -> &str {

crates/nu-command/src/commands/platform/sleep.rs

@@ -21,7 +21,7 @@ impl WholeStreamCommand for Sleep {
     fn signature(&self) -> Signature {
         Signature::build("sleep")
             .required("duration", SyntaxShape::Duration, "time to sleep")
-            .rest(SyntaxShape::Duration, "additional time")
+            .rest("rest", SyntaxShape::Duration, "additional time")
     }
 
     fn usage(&self) -> &str {

crates/nu-command/src/commands/platform/which_.rs

@@ -16,7 +16,7 @@ impl WholeStreamCommand for Which {
     fn signature(&self) -> Signature {
         Signature::build("which")
             .required("application", SyntaxShape::String, "application")
-            .rest(SyntaxShape::String, "additional applications")
+            .rest("rest", SyntaxShape::String, "additional applications")
             .switch("all", "list all executables", Some('a'))
     }