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-cmd-dataframe/src/dataframe/eager/drop_duplicates.rs

@@ -25,7 +25,7 @@ impl Command for DropDuplicates {
         Signature::build(self.name())
             .optional(
                 "subset",
-                SyntaxShape::Table,
+                SyntaxShape::Table(vec![]),
                 "subset of columns to drop duplicates",
             )
             .switch("maintain", "maintain order", Some('m'))

crates/nu-cmd-dataframe/src/dataframe/eager/drop_nulls.rs

@@ -24,7 +24,7 @@ impl Command for DropNulls {
         Signature::build(self.name())
             .optional(
                 "subset",
-                SyntaxShape::Table,
+                SyntaxShape::Table(vec![]),
                 "subset of columns to drop nulls",
             )
             .input_output_type(

crates/nu-cmd-dataframe/src/dataframe/eager/melt.rs

@@ -26,13 +26,13 @@ impl Command for MeltDF {
         Signature::build(self.name())
             .required_named(
                 "columns",
-                SyntaxShape::Table,
+                SyntaxShape::Table(vec![]),
                 "column names for melting",
                 Some('c'),
             )
             .required_named(
                 "values",
-                SyntaxShape::Table,
+                SyntaxShape::Table(vec![]),
                 "column names used as value columns",
                 Some('v'),
             )

crates/nu-cmd-dataframe/src/dataframe/eager/summary.rs

@@ -35,7 +35,7 @@ impl Command for Summary {
             )
             .named(
                 "quantiles",
-                SyntaxShape::Table,
+                SyntaxShape::Table(vec![]),
                 "provide optional quantiles",
                 Some('q'),
             )