postData/putData/deleteData don't check response.ok server errors silently pass as success

[avinxshKD]

getData in crud_http.js checks response.ok before resolving. The other three don't they just resolve with whatever the server sends back, even on 4xx/5xx. So a failed save or delete looks successful to the rest of the app

Also all four functions wrap fetch() in new Promise() for no reason. If fetch throws (network down), the outer promise just hangs forever since the rejection is never forwarded.

Kill the backend and try saving something, zero error feedback. getData already does the right thing, so this was probably just missed for the write methods.

[avinxshKD]

@pradeeban pls let me know if you'd want a PR and d would clean up the promise wrapping at the same time