Feat: DataSource okta_apps

[exitcode0]

I've cherry picked an existing PR and had a crack at implementing this with the terraform provider framework
I'm still pretty clueless with GoLang and would love feedback so I can tweak this as needed

I had some trouble trying to get additional information to work with the dataSource, things like the appSettings, appVisibility, appCredentials - I couldn't figure out how to go about creating an interface for these types, i'd love some guidance on this if possible

[exitcode0]

@duytiennguyen-okta any chance I could trouble you for a code review on this one?
i'd love some guidance on how I should've gone about constructing interfaces for these applications or if i've gone about this in the wrong way

[duytiennguyen-okta]

@exitcode0 hey nice works. The apps seems to works fine and got all the fields you need it seems. Before approval, I just want to know if there is no parameter provider, okta_apps will return all apps? Is that your intention?
data "okta_apps" "test" { }
Also do you want to bring appSettings, appVisibility and appCredentials in still? I can give you an example if you wish