Introduce support to override alert rule name

[themarcelor]

Currently, the alert rule is provisioned with a Title that matches the panel title. The Alert constructor function receives a name argument but misleadingly sets that value as the alert rule's Summary instead of AlertRule.Title.

The provisioned dashboard panels can have generic names like "traffic" or "latency", but their corresponding Alert Rules need to have more specific titles, e.g.:

• my-service traffic alarm
• my-service latency alarm

Hence, this PR will allow the operator to utilize an alert.name() option.

[codecov]

Codecov Report

Merging #234 (bb84610) into master (6867a4a) will decrease coverage by 0.06%.
Report is 1 commits behind head on master.
The diff coverage is 0.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #234      +/-   ##
==========================================
- Coverage   90.08%   90.03%   -0.06%     
==========================================
  Files          92       92              
  Lines        6941     6945       +4     
==========================================
  Hits         6253     6253              
- Misses        543      547       +4     
  Partials      145      145              

Files Changed	Coverage Δ
alert/alert.go	96.39% <0.00%> (-3.61%)	⬇️

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