feat(alerting): Add group-specific configuration to email provider

[appleboy]

Add group-specific to list for email alert

Provides support for paging multiple teams based on the group selector while keeping backward compatibility to the old email configuration manifest

integration per team can be specified in the overrides sections in an array form.

alerting:
  email:
    from: "from@example.com"
    username: "from@example.com"
    password: "hunter2"
    host: "mail.example.com"
    port: 587
    to: "recipient1@example.com,recipient2@example.com"
    overrides:
      - group: "core"
        to: "recipient3@example.com,recipient4@example.com"

ref: #96

Signed-off-by: Bo-Yi Wu appleboy.tw@gmail.com

[codecov-commenter]

Codecov Report

Merging #264 (bf77fb4) into master (0bf2271) will increase coverage by 0.06%.
The diff coverage is 93.33%.

@@            Coverage Diff             @@
##           master     #264      +/-   ##
==========================================
+ Coverage   83.57%   83.64%   +0.06%     
==========================================
  Files          53       53              
  Lines        3434     3448      +14     
==========================================
+ Hits         2870     2884      +14     
  Misses        439      439              
  Partials      125      125              

Impacted Files	Coverage Δ
alerting/provider/email/email.go	72.72% <93.33%> (+9.31%)	⬆️

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[TwiN]

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[TwiN]

Released in v3.7.0