SQL Expressions: Add sql expression specific timeout and output limit (#104834)

Adds settings for SQL expressions:
 sql_expression_cell_output_limit

Set the maximum number of cells that can be returned from a SQL expression. Default is 100000.

sql_expression_timeout

The duration a SQL expression will run before being cancelled. The default is 10s.

pkg/expr/sql/dummy_arm.go

@@ -5,6 +5,7 @@ package sql
 import (
 	"context"
 	"fmt"
+	"time"
 
 	"github.com/grafana/grafana-plugin-sdk-go/data"
 	"github.com/grafana/grafana/pkg/infra/tracing"
@@ -14,6 +15,22 @@ type DB struct{}
 
 // Stub out the QueryFrames method for ARM builds
 // See github.com/dolthub/go-mysql-server/issues/2837
-func (db *DB) QueryFrames(_ context.Context, _ tracing.Tracer, _, _ string, _ []*data.Frame) (*data.Frame, error) {
+func (db *DB) QueryFrames(_ context.Context, _ tracing.Tracer, _, _ string, _ []*data.Frame, _...QueryOption) (*data.Frame, error) {
 	return nil, fmt.Errorf("sql expressions not supported in arm")
 }
+
+func WithTimeout(_ time.Duration) QueryOption {
+	return func(_ *QueryOptions) {
+		// no-op
+	}
+}
+
+func WithMaxOutputCells(_ int64) QueryOption {
+	return func(_ *QueryOptions) {
+		// no-op
+	}
+}
+
+type QueryOptions struct{}
+
+type QueryOption func(*QueryOptions)