Add context menu to display database tables stats (#639)

* Add context menu to display database tables stats

* Move table stats implementation into client

pkg/client/client.go

@@ -335,6 +335,10 @@ func (client *Client) TableConstraints(table string) (*Result, error) {
 	return res, err
 }
 
+func (client *Client) TablesStats() (*Result, error) {
+	return client.query(statements.TablesStats)
+}
+
 // Returns all active queriers on the server
 func (client *Client) Activity() (*Result, error) {
 	if client.serverType == cockroachType {