Global exception handler

[ArtemGet]

For now we provide commands and sends that throws CmdException/SendException, but users dont have tool for global exception handling. I suggest adding such possibility. Class should take on target route and spare route as an attributes, similar to how CmdFork works.

[yanmayak]

@ArtemGet I'll take this one

[yanmayak]

@ArtemGet should I restructure project (create exception directory with handler and SendException/CmdException classes)?
And I see an example in PeriodsBot.java. There is Oprional.empty() as spare route in handleExecution method. Is it general case or special case in handler? Should we log exception handling in general case?

[ArtemGet]

@yanmayak I think that exception handler is an entity related to '''bot''' configuration (we are planning that to be represented in teleroute), so it could be placed in '''bot''' dir.

The idea was to provide an interface to configure global exception handling, lets call it '''Emergency'''. It could be done via sending some default message to user/log or do any other custom logic. I see api usage as:
'''java
new MyBot(
new ERoute(
//spare routes if error thrown by default flow
),
//target routes aka app logic
)
'''

In future we could add chains of '''Emergency''' that wraps each other:

'''java
new MyBot(
new ELog(...),
new ELogKafka(...),
new EPg(...)
new ERoute(
//spare routes if error thrown by default flow
),
//target routes aka app logic
)
'''

I suggest that '''Emergency''' classes would have access to Update(or it's Wrap) and Cmd, that passed in method attributes, so it could execute command and send result quietly (without raising any exceptions), applying any custom logic that user wants if error appears. Lets implement '''ERoute''' that is mentioned in issue description.