- lower `AdaptiveCardMaxVersion` from `1.5` to `1.4`
  - this almost seems like a bug on Teams' end as this limitation is
    not communicated (from what I could tell) via
    https://adaptivecards.io/designer/
  - using a value of `1.4` appears to work equally well for O365 and
    Workflow connectors
- treat a 202 response code as sufficient response verification
  - instead of expecting a `1` in the response body as previously
    confirmed
  - see also #59
- add `logic.azure.com` to valid URL patterns for default validation
- debugging / troubleshooting
    - log status code and response string for O365 connector responses
    - log validation pattern match

refs GH-262

Switch from static base pattern of `logic.azure.com` to a regex
OR pattern to permit either of `logic.azure.com` or
`*.azure-api.net` as has been observed in the wild.

This also has the side effect of resolving potential CodeQL
alerts raised in PR GH-275.

refs GH-262