Move step to a dedicated mod and replace it with an enum

crates/milli/src/update/new/steps.rs

@@ -0,0 +1,45 @@
+use enum_iterator::Sequence;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Sequence)]
+#[repr(u16)]
+pub enum Step {
+    ExtractingDocuments,
+    ExtractingFacets,
+    ExtractingWords,
+    ExtractingWordProximity,
+    ExtractingEmbeddings,
+    WritingGeoPoints,
+    WritingToDatabase,
+    WritingEmbeddingsToDatabase,
+    WaitingForExtractors,
+    PostProcessingFacets,
+    PostProcessingWords,
+    Finalizing,
+}
+
+impl Step {
+    pub fn name(&self) -> &'static str {
+        match self {
+            Step::ExtractingDocuments => "extracting documents",
+            Step::ExtractingFacets => "extracting facets",
+            Step::ExtractingWords => "extracting words",
+            Step::ExtractingWordProximity => "extracting word proximity",
+            Step::ExtractingEmbeddings => "extracting embeddings",
+            Step::WritingGeoPoints => "writing geo points",
+            Step::WritingToDatabase => "writing to database",
+            Step::WritingEmbeddingsToDatabase => "writing embeddings to database",
+            Step::WaitingForExtractors => "waiting for extractors",
+            Step::PostProcessingFacets => "post-processing facets",
+            Step::PostProcessingWords => "post-processing words",
+            Step::Finalizing => "finalizing",
+        }
+    }
+
+    pub fn finished_steps(self) -> u16 {
+        self as u16
+    }
+
+    pub const fn total_steps() -> u16 {
+        Self::CARDINALITY as u16
+    }
+}