Remove unnecessary IssueList attribute loads

[ethantkoenig]

IssueList.loadAttributes() loads attachments and comments, but these fields are rarely used for lists of issues. This PR updates IssueList.loadAttributes() to load everything except attachments and comments, and add separate methods for explicitly loading attachments/comments.

[codecov-io]

Codecov Report

Merging #2936 into master will decrease coverage by 0.19%.
The diff coverage is 0%.

@@           Coverage Diff            @@
##           master   #2936     +/-   ##
========================================
- Coverage      27%   26.8%   -0.2%     
========================================
  Files          90      90             
  Lines       17806   17807      +1     
========================================
- Hits         4809    4774     -35     
- Misses      12310   12353     +43     
+ Partials      687     680      -7

Impacted Files	Coverage Δ
models/issue_list.go	50.6% <0%> (-12.45%)	⬇️
models/issue_indexer.go	7.79% <0%> (-0.32%)	⬇️
modules/process/manager.go	69.56% <0%> (-4.35%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 10b54df...1721cfa. Read the comment docs.

[lunny]

@ethantkoenig if any place which reference LoadAttributes really needs comments or attachments?

[ethantkoenig]

@lunny Only in models/issue_indexer.go (which needs comments), and I've added a call to LoadComments(..) there

[lunny]

LGTM

[lafriks]

LGTM