allow tables to have annotations (#9613)

# Description

follow up to #8529 and #8914

this works very similarly to record annotations, only difference being
that

```sh
table<name: string>
      ^^^^  ^^^^^^
      |     | 
      |     represents the type of the items in that column
      |
      represents the column name
```
more info on the syntax can be found
[here](https://github.com/nushell/nushell/pull/8914#issue-1672113520)

# User-Facing Changes

**[BREAKING CHANGE]**
this change adds a field to `SyntaxShape::Table` so any plugins that
used it will have to update and include the field. though if you are
unsure of the type the table expects, `SyntaxShape::Table(vec![])` will
suffice

crates/nu-command/src/conversions/into/duration.rs

@@ -23,6 +23,7 @@ impl Command for SubCommand {
                 // TODO: --convert option should be implemented as `format duration`
                 (Type::String, Type::String),
                 (Type::Duration, Type::String),
+                (Type::Table(vec![]), Type::Table(vec![])),
             ])
             .named(
                 "convert",