* simplify gobject JSON format, remove unused fields
This allows gobject format to change from (for example):
```
[
[
"proposal",
{"object": "data-here"}
]
]
```
... to simply:
```
{"object": "data-here"}
```
The outer array isn't needed, and the first value in the 2-item tuple is
likewise discarded by DashCore. This change should allow either data
format to exist (we can deprecate/remove the older format later) and
remove the array of different type elements (string, object).
* validator test for legacy and new proposal formats
* Refactor CProposalValidator
- fix names
- MAX_NAME_SIZE instead of magic value
- move most functions to private, test actual usage (constructor and Validate), not every single function
- do not store hex string (there is no reason to do so anymore)
- remove (now) unused functions
* Make sure payment_address has no whitespaces
* Fix governance_validators_tests
* Don't allow whitespaces, drop StripWhitespaces and add corresponding tests
* Show validator internal errors on check failure
* Implement proposal validation
Includes commits:
Implemented CProposalValidator
Use CProposalValidator to check proposals at prepare and submit stages
Modify proposal validator to support numerical data in string format
Multiple bug fixes in governance-validators.cpp
Fixed bug in CheckURL
Fixed stream state check
Increase strictness of payment address validation for compatibility with sentinel
Improved error reporting
Implemented "check" rpc command to validate proposals
Fixes to RPC check command
Fix error message
Unit test and data files for proposal validator
Added test cases
Removed debugging code
* Fix name validation
* Changes to address code review comments
