ESQL: Normalize timeseries aggs slightly

Time series aggregations needed a method like:
```
static Block evaluateFinal(
  GroupingState state, IntVector selected, GroupingAggregatorEvaluationContext ctx
)
```

and other aggregations needed to write it:
```
static Block evaluateFinal(
  GroupingState state, IntVector selected, DriverContext ctx
)
```

While slightly shorter, it isn't worth having two ways to do it. This is
purely mechanical change to make everything work like the time series
aggregations.

It also adds a few more of the "we're not sorting these imports"
comments to the template generated classes.

Relates to #108385

Author: nik9000

x-pack/plugin/esql/compute/gen/src/main/java/org/elasticsearch/compute/gen/GroupingAggregatorImplementer.java

@@ -724,11 +724,11 @@ private MethodSpec evaluateFinal() {
             .addParameter(BLOCK_ARRAY, "blocks")
             .addParameter(TypeName.INT, "offset")
             .addParameter(INT_VECTOR, "selected")
-            .addParameter(GROUPING_AGGREGATOR_EVALUATOR_CONTEXT, "evaluatorContext");
+            .addParameter(GROUPING_AGGREGATOR_EVALUATOR_CONTEXT, "ctx");
 
         if (aggState.declaredType().isPrimitive()) {
-            builder.addStatement("blocks[offset] = state.toValuesBlock(selected, evaluatorContext.driverContext())");
-        } else if (timseries) {
+            builder.addStatement("blocks[offset] = state.toValuesBlock(selected, ctx.driverContext())");
+        } else {
             requireStaticMethod(
                 declarationType,
                 requireType(BLOCK),
@@ -739,15 +739,7 @@ private MethodSpec evaluateFinal() {
                     requireType(GROUPING_AGGREGATOR_EVALUATOR_CONTEXT)
                 )
             );
-            builder.addStatement("blocks[offset] = $T.evaluateFinal(state, selected, evaluatorContext)", declarationType);
-        } else {
-            requireStaticMethod(
-                declarationType,
-                requireType(BLOCK),
-                requireName("evaluateFinal"),
-                requireArgs(requireType(aggState.declaredType()), requireType(INT_VECTOR), requireType(DRIVER_CONTEXT))
-            );
-            builder.addStatement("blocks[offset] = $T.evaluateFinal(state, selected, evaluatorContext.driverContext())", declarationType);
+            builder.addStatement("blocks[offset] = $T.evaluateFinal(state, selected, ctx)", declarationType);
         }
         return builder.build();
     }