ls, rm, cp, open, touch, mkdir: Don't expand tilde if input path is quoted string or a variable. (#12232)

# Description
Fixes:  #11887
Fixes: #11626

This pr unify the tilde expand behavior over several filesystem relative
commands. It follows the same rule with glob expansion:
|  command  |  result |
| ----------- |  ------ |
| ls ~/aaa  | expand tilde
| ls "~/aaa"  | don't expand tilde
| let f = "~/aaa"; ls $f | don't expand tilde, if you want to: use `ls
($f \| path expand)`
| let f: glob = "~/aaa"; ls $f | expand tilde, they don't expand on
`mkdir`, `touch` comamnd.

Actually I'm not sure for 4th item, currently it's expanding is just
because it followes the same rule with glob expansion.

### About the change
It changes `expand_path_with` to accept a new argument called
`expand_tilde`, if it's true, expand it, if not, just keep it as `~`
itself.

# User-Facing Changes
After this change, `ls "~/aaa"` won't expand tilde.

# Tests + Formatting
Done

crates/nu-command/src/env/load_env.rs

@@ -70,7 +70,7 @@ impl Command for LoadEnv {
                         if env_var == "PWD" {
                             let cwd = current_dir(engine_state, stack)?;
                             let rhs = rhs.coerce_into_string()?;
-                            let rhs = nu_path::expand_path_with(rhs, cwd);
+                            let rhs = nu_path::expand_path_with(rhs, cwd, true);
                             stack.add_env_var(
                                 env_var,
                                 Value::string(rhs.to_string_lossy(), call.head),