refactor(rome_js_formatter): Move node formatting into its own trait

Today, the formatting that must happen for each JS node happens inside `Formatter.format_syntax_node` and the `formatter_traits`.

This PR moves the common logic applied by all nodes and tokens into the `ToFormatElement` implementation and renames it to `Format`.

* Rename `ToFormatElement` to `Format` and `to_format_element` to `format`
* Implement `Format` for `JsSyntaxToken`. CSS, JSON etc. can implement their own generic token formatting logic
* Introduce a new `FormatNode` trait (language specific) that implements the formatting of a node and calls into `format_fields` that is implemented for each field.
* Make the `FormatterTraits` node and language independent. Rename to `FormatTraits`.

`Format`, `FormatterTraits`, `FormatResult`, and `FormatError` are now all language independent. However, some still depend on the `Formatter`.

The next step is to move many of the `Formatter`'s helper function out of the Formatter so that it becomes language independent.

crates/rome_js_formatter/src/cst.rs

@@ -1,8 +1,8 @@
-use crate::{FormatElement, FormatResult, Formatter, ToFormatElement};
+use crate::{Format, FormatElement, FormatResult, Formatter};
 use rome_js_syntax::{map_syntax_node, JsSyntaxNode};
 
-impl ToFormatElement for JsSyntaxNode {
-    fn to_format_element(&self, formatter: &Formatter) -> FormatResult<FormatElement> {
-        map_syntax_node!(self.clone(), node => node.to_format_element(formatter))
+impl Format for JsSyntaxNode {
+    fn format(&self, formatter: &Formatter) -> FormatResult<FormatElement> {
+        map_syntax_node!(self.clone(), node => node.format(formatter))
     }
 }