unify iso naming in Now (#631)

Deprecate `Now::plain_time_with_provider` and rename it to
`Now::plain_time_iso_with_provider`

Author: Sharktheone

src/builtins/compiled/now.rs

@@ -38,6 +38,6 @@ impl<H: HostHooks> Now<H> {
     ///
     /// Enable with the `compiled_data` and `sys` feature flags.
     pub fn plain_time_iso(self, time_zone: Option<TimeZone>) -> TemporalResult<PlainTime> {
-        self.plain_time_with_provider(time_zone, &*TZ_PROVIDER)
+        self.plain_time_iso_with_provider(time_zone, &*TZ_PROVIDER)
     }
 }

src/builtins/core/now.rs

@@ -90,10 +90,24 @@ impl<H: HostHooks> Now<H> {
     ///
     /// When `TimeZone` is `None`, the value will default to the
     /// system time zone or UTC if the system zone is unavailable.
+    /// Deprecated: Use `plain_time_iso_with_provider` instead.
+    #[deprecated(since = "0.1.2", note = "Use `plain_time_iso_with_provider` instead")]
     pub fn plain_time_with_provider(
         self,
         time_zone: Option<TimeZone>,
         provider: &(impl TimeZoneProvider + ?Sized),
+    ) -> TemporalResult<PlainTime> {
+        self.plain_time_iso_with_provider(time_zone, provider)
+    }
+
+    /// Converts `Now` into the current system [`PlainTime`].
+    ///
+    /// When `TimeZone` is `None`, the value will default to the
+    /// system time zone or UTC if the system zone is unavailable.
+    pub fn plain_time_iso_with_provider(
+        self,
+        time_zone: Option<TimeZone>,
+        provider: &(impl TimeZoneProvider + ?Sized),
     ) -> TemporalResult<PlainTime> {
         let iso = self.system_datetime_with_provider(time_zone, provider)?;
         Ok(PlainTime::new_unchecked(iso.time))