New data structures

A new structure will be added, that includes the ResticConfig inline and extends this with one new parameter UploaderType:

type NodeAgentConfig struct

Configuration YAML options

The nodeAgent configuration options and restic configuration options will be exactly the same and will contain same options as the current restic schema with additional uploaderType field under nodeAgent. The part of YAML that presents the additions:

Deprecation of the restic configuration option in OADP 1.3 and it's future removal

The restic configuration option will be deprecated in OADP 1.3. It will be removed in a future OADP release. However, restic backup functionality is still fully-supported, but restic users are encouraged to use the new nodeAgent configuration option instead, so that they won't be impacted on upgrade when the legacy struct is removed in a future release.

Documentation required

oadp-installing-dpa.adoc

1. On line 11 - change title to include (OADP 1.2 and earlier)
2. Duplicate page using `Save as` calling the new file something like oadp-install-dpa.adoc to oadp-install-dpa-1-3.adoc
3. Add changes. Include that Kopia is the recommended option
4. Update TOC to include title
5. Go into each assembly add new module created in step 2 below `oadp-install-dpa.adoc`
6. Add note about roadmap