Log module should escape invalid characters properly in JSON and other supported formats

[nadundesilva]

Description:
Currently, invalid characters in logs are not properly formatted and therefore results in malformed log lines. We need to investigate on the invalid characters in the supported formats and escape them accordingly.

Found the following characters that cause the log lines to be malformed

• \n
• "

Steps to reproduce:
Use the following code

import ballerina/log;

public function main() {
    log:printError("Request received from user \"nadun\"");
    log:printError("New line test \n test log end");
}

JSON Log Output:

{"time": "2021-03-31 14:11:09,906", "level": "ERROR", "module": "nadun/test_logs", "message": "Request received from user "nadun""}
{"time": "2021-03-31 14:11:09,931", "level": "ERROR", "module": "nadun/test_logs", "message": "New line test
 test log end"}

Normal Log Output:

time = 2021-03-31 14:12:12,890 level = ERROR module = nadun/test_logs message = "Request received from user "nadun""
time = 2021-03-31 14:12:12,909 level = ERROR module = nadun/test_logs message = "New line test
 test log end

Affected Versions:
Ballerina Swan Lake Alpha 4