Wk issue #22 unit tests (#36)

* Issue #22: t_proposal_database_fixture struct update.

* Issue #22: t_proposal_database_fixture struct update.

* Issue #22: t_proposal_database_fixture struct update.

* Unit tests skeleton for SPS main commands.

* More unitests for create_proposal.

* Unitests: create proposal arguments validation.

* Unitests for remove proposal operation.

* Unitest for removal proposals with votes.

* Remove of FIND_VOTE macro and more unitestes for remove proposal.

* Unittest for update proposal command.

* AUthorization validation unitests for proposal commands.

* Issue #22: t_proposal_database_fixture struct update.

* Issue #22: t_proposal_database_fixture struct update.

* Issue #22: t_proposal_database_fixture struct update.

* Unit tests skeleton for SPS main commands.

* More unitests for create_proposal.

* Unitests: create proposal arguments validation.

* Unitests for remove proposal operation.

* Unitest for removal proposals with votes.

* Remove of FIND_VOTE macro and more unitestes for remove proposal.

* Unittest for update proposal command.

* AUthorization validation unitests for proposal commands.

* Rebase/upmerge changes.

* Rebase/upmerge fixes cnt.