Pushover title template variables

[m4rcu5]

Hi,

It seems that the Pushover alert service does not support template variables in the title parameter.

Example use-case:

state_data  
  |window()
    .period(150m)
    .every(5m)
    .fillPeriod()
  |mode('code')
    .as('state_code')
  |alert()
    .info(lambda: "state_code" <= 3)
    .stateChangesOnly()

    .message('<Detailed alert info goes here>') 

    .pushover()
      .title('{{ .Level }} System Alert: {{ index .Tags "name" }} on {{ index .Tags "cloud" }}')

Would it be possible to support templating in the title parameter?