RFR: 1851: Fold CSR bot into PR bot [v2]

[Zhao Song]

> In this patch, the whole csr bot module is removed. 
> 
> Original CSRPullRequestBot is deleted. The functionality of this bot has been moved to `CheckRun`.
> 
> Original CSRIssueBot has been moved to pr bot module. PullRequestBotFactory would generate a CSRIssueBot for every configured Issue project.

Zhao Song has updated the pull request incrementally with one additional commit since the last revision:

  fix problems

-------------

Changes:
  - all: https://git.openjdk.org/skara/pull/1492/files
  - new: https://git.openjdk.org/skara/pull/1492/files/a048bd7b..d0a0d2f0

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=skara&pr=1492&range=01
 - incr: https://webrevs.openjdk.org/?repo=skara&pr=1492&range=00-01

  Stats: 55 lines in 8 files changed: 13 ins; 4 del; 38 mod
  Patch: https://git.openjdk.org/skara/pull/1492.diff
  Fetch: git fetch https://git.openjdk.org/skara.git pull/1492/head:pull/1492

PR: https://git.openjdk.org/skara/pull/1492