perf: gracefully parse ResultValue from output

[vladopajic]

when running client, parsing ResultValue from ostdout lines can throw exception if line could not be parsed.

in order to help developers, new console.error was added to display line that caused error.

also, error will be swallowed, which will give more robustness in running client as it will tolerated non json lines in the output.

---

PR inspired by
#658 (comment)

=== Starting client nim-libp2p/v1.10/tcp
/home/runner/work/test-plans/test-plans/perf/runner/src/index.ts:211
        const result = JSON.parse(line) as ResultValue;
                            ^
SyntaxError: Unexpected end of JSON input
    at JSON.parse (<anonymous>)
    at runClient (/home/runner/work/test-plans/test-plans/perf/runner/src/index.ts:211:29)
    at runBenchmarkAcrossVersions (/home/runner/work/test-plans/test-plans/perf/runner/src/index.ts:150:28)
    at main (/home/runner/work/test-plans/test-plans/perf/runner/src/index.ts:23:9)
    at Object.<anonymous> (/home/runner/work/test-plans/test-plans/perf/runner/src/index.ts:271:1)
    at Module._compile (node:internal/modules/cjs/loader:1529:14)
    at Module.m._compile (/home/runner/work/test-plans/test-plans/perf/runner/node_modules/ts-node/src/index.ts:1618:23)
    at Module._extensions..js (node:internal/modules/cjs/loader:1613:10)
    at Object.require.extensions.<computed> [as .ts] (/home/runner/work/test-plans/test-plans/perf/runner/node_modules/ts-node/src/index.ts:1621:12)
    at Module.load (node:internal/modules/cjs/loader:1275:32)