use ParseAuthorizedKey instead of string parsing of the public key

[Xeckt]

Few changes in this pull request, more than anticipated:

• Remove publickey struct and use only ssh.publickey interface
• Taking advantage of the ssh.PublicKey Type() func to get a keys exact type for the publicKey struct:
• Removed the len check on how many fields were detected in the string, ParseAuthorizedKey func will detect if it's a valid key or not
• Changed the createtempfile func for testing to be more inclusive of it's intention, moved the dhcp string for testing to a constant in the daemon_test.go file
• moved ssh logic into it's own file with tests
• added helper functions for getting ssh strings

I hope all these changes are okay. Let me know if you would like to change anything or revert any of the changes. All tests have passed locally, including daemon tests.

[Xeckt]

Sorry for the title changes I borked up some stuff :D

On second consideration, it might be better to keep the struct field I changed to type as Algorithm

[glimchb]

Thanks @Xeckt for the contribution
This is exactly the direction I was looking for
Few small comments inside, once fixed, we can merge this PR

[Xeckt]

Thanks for the feedback! Will make the changes later today!

[Xeckt]

All changes and feedback resolved. Let me know if the new changes are ok!

[glimchb]

looks great, thansk @Xeckt for contributing and fixing all issues
please add copyright in the new file and fix few ci failures we good to merge
at this point you can also squash all commit into a single one, review is done

[Xeckt]

Linter issues fixed, ran golangci-lint locally, seems all good.

[Xeckt]

Commits squashed!

[glimchb]

@Xeckt please note https://commitlint.js.org/ failing

[Xeckt]

Gah! Sorry!

[glimchb]

Gah! Sorry!

no worries. just add fix: or feat: in the start of the commit message and keep it lowercase...

[Xeckt]

Should be done now