add prefix to more error messages to improve DX

[jackson-yyy]

rollup-plugin-typescript2/src/parse-tsconfig.ts

Line 27 in 4e9f8ff

throw new Error(`failed to read '${fileName}'`);

for this example, it could be like throw new Error(`rpt2: failed to read '${fileName}'`)

if you allow, i can provide a pull request later, covering the whole project.

[ezolenko]

I added prefixes in master, let me know if I missed any

[agilgur5]

Released in 0.32.0

[agilgur5]

let me know if I missed any

Got the remaining few in #382 .

Also, for other readers, per that PR, the vast majority of errors were already auto-prefixed by RollupContext and ConsoleContext.
Only a handful of errors were thrown in the options hook, which does not implement Rollup's this.error, and so some prefixes were missing since they do not go through the above logging wrappers and must be manually prefixed as such.