ssh_config: Add 'forwardagent' option (#3495)

* Integration Tests for Options added, includes 'proxycommand'

* New option 'forwardagent' added to integration tests

* Missing double quotes added to 'forwardagent' values to enforce handling as string

* New option 'forwardagent' added

* yamllint error resolved

* 'forwardagent' type changed from str to choices (yes/no)

* Changelog added

* correct typo

Co-authored-by: Felix Fontein <felix@fontein.de>

* version info added to new option

Co-authored-by: Felix Fontein <felix@fontein.de>

* fix(ssh_config): option name to snake_case, type str to bool

* fix(ssh_config): convert bool true/false to str yes/no

* fix(ssh_config): rename option to 'forward_agent' in integration test

* fix(ssh_config): args key 'forwardagent' renamed to 'forward_agent'

* fix(ssh_config): 'else' replaced with 'if' statement to cover case when value is 'None'

* increase version_added to 4.0.0

Co-authored-by: Felix Fontein <felix@fontein.de>

* simplify if statement for True/False to yes/no mapping

Co-authored-by: Felix Fontein <felix@fontein.de>

* update comment to better describe functionality

Co-authored-by: Felix Fontein <felix@fontein.de>

* fix(ssh_config): avoid overwrite of existing option in case of None value

* test(ssh_config): case added to verify no changes on existing option if not given in playbook

Co-authored-by: Felix Fontein <felix@fontein.de>

changelogs/fragments/3495-ssh_config_add_forwardagent_option.yml

@@ -0,0 +1,3 @@
+minor_changes:
+  - ssh_config - new feature to set ``ForwardAgent`` option to ``yes`` or ``no`` 
+    (https://github.com/ansible-collections/community.general/issues/2473).