Add configuration flow abilites to the ld2410 component (#4434)

esphome/components/ld2410/number/gate_threshold_number.cpp

@@ -0,0 +1,14 @@
+#include "gate_threshold_number.h"
+
+namespace esphome {
+namespace ld2410 {
+
+GateThresholdNumber::GateThresholdNumber(uint8_t gate) : gate_(gate) {}
+
+void GateThresholdNumber::control(float value) {
+  this->publish_state(value);
+  this->parent_->set_gate_threshold(this->gate_);
+}
+
+}  // namespace ld2410
+}  // namespace esphome