Contract schema tuple variants handling

[MissingNO57]

_extract_msgs can't handle tuple variants and returns
'upload_logo' = {dict: 0} {}

Most of the contracts are using named fields

pub enum ExecuteMsg {
   UpdateMinter { new_minter: Option<String> },
}

This would be called like

{"update_minter" : {"new_minter": "something"}}

But for example cw20-base contract uses tuple variants that have no name:

pub enum ExecuteMsg {
    UploadLogo(Logo),
}

pub enum Logo {
    /// A reference to an externally hosted logo. Must be a valid HTTP or HTTPS URL.
    Url(String),
    /// Logo content stored on the blockchain. Enforce maximum size of 5KB on all variants
    Embedded(EmbeddedLogo),
}

In the case of tuple variant execution message would look like this:

  "upload_logo": {
    "url": "https://example.com/logo.png"
  }
}

This is named fields schema

...
 'properties' = {dict: 1} {'send': {'additionalProperties': False, 'properties': {'amount': {'$ref': '#/definitions/Uint128'}, 'contract': {'type': 'string'}, 'msg': {'$ref': '#/definitions/Binary'}}, 'required': ['amount', 'contract', 'msg'], 'type': 'object'}}
  'send' = {dict: 4} {'additionalProperties': False, 'properties': {'amount': {'$ref': '#/definitions/Uint128'}, 'contract': {'type': 'string'}, 'msg': {'$ref': '#/definitions/Binary'}}, 'required': ['amount', 'contract', 'msg'], 'type': 'object'}
...

This is a tuple variant schema:

...
 'properties' = {dict: 1} {'upload_logo': {'$ref': '#/definitions/Logo'}}
...