5V support for TAS2780

[gnumpi]

• Enables the TAS2780 to operate at voltages below 9V using Power Mode 0.
• Maintains backward compatibility by keeping the TAS2780 in Power Mode 2 for voltages 9V and above.
• If the TAS2780 enters SOFTWARE_SHUTDOWN due to an error, ESPHome logs will now indicate the interrupt source that triggered the shutdown.
• Sets the maximum DVC attenuation to -80 dB, corresponding to a minimum volume level of 0.2.

Requires PR #302 to function correctly.

[that1guy]

@gnumpi per this comment in previous PR, do we have min_vol & dBV set correctly per speaker tier? #297 (comment)

[gnumpi]

@gnumpi per this comment in previous PR, do we have min_vol & dBV set correctly per speaker tier? #297 (comment)

ohhh you are right, you wanted the minimum level set to 0.3, somehow I remembered 0.2. I will fix that.
There are no speaker presets yet.

[gnumpi]

@gnumpi per this comment in previous PR, do we have min_vol & dBV set correctly per speaker tier? #297 (comment)

ohhh you are right, you wanted the minimum level set to 0.3, somehow I remembered 0.2. I will fix that.

done, the minimum of the volume slider will now set the volume to 0.3 (-70dB attenuation)

[alextrical]

Changes look good to me