[EN-1502] Refactor manifest creation for legacy connectors

[rukolahasser]

It's hard to migrate some legacy connectors to the new repo, so we need a way to create manifest manually.

[cnkarz]

I think @azhang wants to keep manifest limiting. What issue did you have? Why did you need to make it so?

[rukolahasser]

I think @azhang wants to keep manifest limiting. What issue did you have? Why did you need to make it so?

@cnkarz It's kinda hard to migrate traderjoe to the new connectors repo, so i don't want it to crash when manifest file doesn't exist.
You can call it like this:

m := connector.CreateManifest("traderjoe", "nakji", "0.0.0")

c, err := connector.NewConnector(connector.WithManifest(m))
if err != nil {
    log.Error().Err(err).Msg("failed to instantiate connector")
}

in this way you can override manifest on instantiation.

[cnkarz]

I don't understand why this can't be included in a manifest file. Or do you need additional functionality?
Also the code is quite confusing. Why not just pass the manifest object to NewConnector directly and set it as c.manifest = m ?

[rukolahasser]

@cnkarz

1. Because in the blep repo, the working dir is different, so it can't be included in the manifest file.
2. The manifest field is not exported, so we cannot access it, also it will panic when it reaches c.id().
3. I'm trying to change as little code as possible to make it work cuz many connectors are dependent on it.