Only change hvac_action to idle when mode changes

[ErikT80]

This PR should fix a bug where the hvac_action is set to idle if any setting on the heatpump is changed.

Should fix #110

Changes:

• When heatpump settings change check if the component mode is not the same as the mode from the heatpump. When this is the case update the component mode and set the hvac_action to idle. Otherwise only check if the heat or cool setpoint differ and update.

@geoffdavis Would be nice if you can take a look whether I overlooked anything, tested it locally and seems fine for my heatpumps (msz-hr25vf, msz-hr35vf & msz-hr50vf)