## Changes
Added JSON input validation for CLI commands. Now when invalid JSON
passed as a payload to CLI commands, CLI performs input normalisation
and detects if there are any mismatches such as incorrect types, unknown
fields and etc.
This diagnostic information is printed in standard error output and does
not block command execution, so the change is backward compatible.
Fixes#1769#1764#1625#1560
## Tests
Added unit tests
```
andrew.nester@HFW9Y94129 ~ % databricks jobs create --json '{"seeti}'
Error: error decoding JSON at (inline):1:2: unexpected EOF
andrew.nester@HFW9Y94129 ~ % databricks jobs create --json '{"seeti": true}'
Warning: unknown field: seeti
in (inline):1:9
Error: Job settings must be specified.
```
---------
Co-authored-by: Pieter Noordhuis <pieter.noordhuis@databricks.com>
## Changes
Generated commands relied on global variables for flags and request
payloads. This is difficult to test if a sequence of tests tries to run
the same command with various arguments because the global state causes
test interference. Moreover, it is impossible to run tests in parallel.
This change modifies the approach and turns every command group and
command itself into a function that returns a `*cobra.Command`. All
flags and request payloads are variables scoped to the command's
initialization function. This means it is possible to construct
independent copies of the CLI structure and fixes the test isolation
issue.
The scope of this change is only the generated commands. The other
commands will be changed accordingly in subsequent changes.
## Tests
Unit and integration tests pass.