PS-10012 feature: Extend connection section of the configuration file with SSL parameters

[percona-ysorokin]

https://perconadev.atlassian.net/browse/PS-10012

Added two new optional subsections to the 'connection' section of the main configuration file:

• 'ssl' (with 'mode', 'ca', 'capath', 'crl', 'crlpath', 'cert', 'key', and 'cipher' parameters)
• 'tls' (with 'ciphersuites' and 'version' parameters)

As the configuration file now includes optional parameters / sections, providing them as a plain list as command line arguments is no longer possible. So, this functionality was removed. The only possible option to run the program is "binlog_server (fetch|pull)) <json_config_file>".
As the result of this change the 'nv_tuple_from_command_line.hpp' header with helper functions was deleted.

Reworked helper function in the 'nv_tuple_from_json.hpp' header file to support optional JSON parameters (those that are represented with 'std::optional<>').

Main application now prints more info from the configuration file to the log.

'main_config.json' example configuration file extended with new 'ssl' and 'tls' subsections.

Refactored MTR test cases:

• Extracted 'have_binsrv.inc' MTR include file that ensures that test cases are run with the '$BINSRV' environment variable pointing to the binlog utility binary is properly set.
• Extracted 'detect_connection_user_and_host.inc' MTR include file that extracts 'user' and 'host' components from the value returned by the 'USER()' function.
• it is now possible to specify custom 'user' and 'host' parameters that will be put into the JSON configuration file in 'set_up_binsrv_environment.inc' MTR include file.
• 'set_up_binsrv_environment.inc' MTR include file is now capable of generation 'ssl' and 'tls' section in the JSON configuration file.

Added new 'binlog_streaming.ssl_connection' MTR test case that runs binlog server utility in variety of SSL connection modes.

Updated 'README.md' with SSL/ TLS connection parameter description.