Change log file prefix from "SMTPFAILED" etc to more descriptive prefixes

[mountaindude]

SMTPFAILED and other similar prefixes in the Butler log files (and in the console log) has proven to be confusing for Butler users. Change it to something more descriptive, for example "TASK FAILED ALERT EMAIL".

For example:

2022-05-02T12:09:11.877Z info: SMTPFAILED: Rate limiting ok: Sending reload failure notification email for task "Manually triggered reload of Always failing reload (no delay)"

Same thing for other alert email prefixes:

SMTPFAILED > "TASK FAILED ALERT EMAIL"
SIGNL4FAILED > "TASK FAILED ALERT SIGNL4"
NEWRELIC TASK FAIL > "TASK FAILED ALERT NEWRELIC"
SLACKFAILED > "TASK FAILED ALERT SLACK"
TEAMSFAILED > "TASK FAILED ALERT TEAMS"

SMTPABORTED > "TASK ABORTED ALERT EMAIL"
SIGNL4ABORTED > "TASK ABORTED ALERT SIGNL4"
NEWRELIC TASK ABORTED > "TASK ABORTED ALERT NEWRELIC"
SLACKABORTED > "TASK ABORTED ALERT SLACK"
TEAMSABORTED > "TASK ABORTED ALERT TEAMS"