Improve fetch-api

[kuuak]

• restore try/catch in api-fetch
• Improve error display
• handle errors of JSON parsing
• return fetched data even if there are errors in the response cc. @geck1942

I did a quick check about the performances concern of first parsing to text then parsing to JSON vs directly parsing to JSON. There is not significant deterioration or improvement in performances. I created a quick jsperf test to compare. Claude.ai also indicate that it should not change anything in perf, it's just a matter of readability

[geck1942]

Excellent! I'm glad there is no much performance impact so I'm all in on the PR