Apply #[derive(Default)] fixes suggested by Clippy (#2000)

These were bugging me every time I ran `clippy` 😁

src/logging.rs

@@ -44,13 +44,14 @@ macro_rules! notify_user {
     }
 }
 
-#[derive(Debug, PartialOrd, Ord, PartialEq, Eq)]
+#[derive(Debug, Default, PartialOrd, Ord, PartialEq, Eq)]
 pub enum LogLevel {
     // No output (+ `log::LevelFilter::Off`).
     Silent,
     // Only show lint violations, with no decorative output (+ `log::LevelFilter::Off`).
     Quiet,
     // All user-facing output (+ `log::LevelFilter::Info`).
+    #[default]
     Default,
     // All user-facing output (+ `log::LevelFilter::Debug`).
     Verbose,
@@ -67,12 +68,6 @@ impl LogLevel {
     }
 }
 
-impl Default for LogLevel {
-    fn default() -> Self {
-        LogLevel::Default
-    }
-}
-
 pub fn set_up_logging(level: &LogLevel) -> Result<()> {
     fern::Dispatch::new()
         .format(|out, message, record| {

src/rules/isort/types.rs

@@ -4,18 +4,13 @@ use rustc_hash::FxHashMap;
 
 use crate::ast;
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
 pub enum TrailingComma {
     Present,
+    #[default]
     Absent,
 }
 
-impl Default for TrailingComma {
-    fn default() -> Self {
-        TrailingComma::Absent
-    }
-}
-
 #[derive(Debug, Hash, Ord, PartialOrd, Eq, PartialEq, Clone)]
 pub struct ImportFromData<'a> {
     pub module: Option<&'a str>,

src/source_code/stylist.rs

@@ -49,18 +49,13 @@ impl<'a> Stylist<'a> {
 }
 
 /// The quotation style used in Python source code.
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, Default, PartialEq, Eq)]
 pub enum Quote {
     Single,
+    #[default]
     Double,
 }
 
-impl Default for Quote {
-    fn default() -> Self {
-        Quote::Double
-    }
-}
-
 impl From<Quote> for char {
     fn from(val: Quote) -> Self {
         match val {
@@ -123,19 +118,14 @@ impl Deref for Indentation {
 
 /// The line ending style used in Python source code.
 /// See <https://docs.python.org/3/reference/lexical_analysis.html#physical-lines>
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, Default, PartialEq, Eq)]
 pub enum LineEnding {
+    #[default]
     Lf,
     Cr,
     CrLf,
 }
 
-impl Default for LineEnding {
-    fn default() -> Self {
-        LineEnding::Lf
-    }
-}
-
 impl Deref for LineEnding {
     type Target = str;