feat: support request-level insert WAL skipping (#9088)

* refactor: add skip_wal fields to internal write requests

Signed-off-by: WenyXu <wenymedia@gmail.com>

* chore(deps): update greptime-proto for insert skip_wal

Signed-off-by: WenyXu <wenymedia@gmail.com>

* feat(mito): support request-level WAL skipping

Signed-off-by: WenyXu <wenymedia@gmail.com>

* feat(metric-engine): handle request-level WAL policies

Signed-off-by: WenyXu <wenymedia@gmail.com>

* feat: propagate insert WAL policy through query context

Signed-off-by: WenyXu <wenymedia@gmail.com>

* feat: support session-level insert WAL policy via SET

Signed-off-by: WenyXu <wenymedia@gmail.com>

* fix(metric-engine): require uniform WAL policy in batch puts

Signed-off-by: WenyXu <wenymedia@gmail.com>

* test(metric-engine): simplify WAL policy coverage

Signed-off-by: WenyXu <wenymedia@gmail.com>

* refactor(servers): simplify gRPC hint extraction

Signed-off-by: WenyXu <wenymedia@gmail.com>

* test: flatten Mito and Metric WAL scenario orchestration

Signed-off-by: WenyXu <wenymedia@gmail.com>

* refactor: separate WAL and memtable-only mutations

Signed-off-by: WenyXu <wenymedia@gmail.com>

* refactor: carry skip-WAL policy in table insert requests

Signed-off-by: WenyXu <wenymedia@gmail.com>

* test: flatten skip-WAL policy cases

Signed-off-by: WenyXu <wenymedia@gmail.com>

* refactor: clarify WAL notifier naming

Signed-off-by: WenyXu <wenymedia@gmail.com>

* chore: pin merged skip-WAL proto revision

Signed-off-by: WenyXu <wenymedia@gmail.com>

---------

Signed-off-by: WenyXu <wenymedia@gmail.com>

src/table/src/requests.rs

@@ -714,6 +714,8 @@ pub struct InsertRequest {
     pub schema_name: String,
     pub table_name: String,
     pub columns_values: HashMap<String, VectorRef>,
+    /// Whether this insert should skip WAL.
+    pub skip_wal: bool,
 }
 
 /// Delete (by primary key) request