Add org struct fields

[kuhlman-labs]

The update an organization API has additional configurable fields that the Organization struct does not support:

WebCommitSignoffRequired
AdvancedSecurityEnabledForNewRepos
DependabotAlertsEnabledForNewRepos
DependabotSecurityUpdatesEnabledForNewRepos
DependencyGraphEnabledForNewRepos
SecretScanningEnabledForNewRepos
SecretScanningPushProtectionEnabledForNewRepos

Proposing adding these fields to enable them to be configurable with Organization.Edit

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[codecov]

Codecov Report

Merging #2471 (9b0e7fc) into master (30d1431) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2471   +/-   ##
=======================================
  Coverage   98.03%   98.03%           
=======================================
  Files         122      122           
  Lines       10695    10695           
=======================================
  Hits        10485    10485           
  Misses        144      144           
  Partials       66       66           

Impacted Files	Coverage Δ
github/orgs.go	96.90% <ø> (ø)

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[gmlewis]

Thank you, @kuhlman-labs !
LGTM.
Merging.