🔊 Reduce breakpoint activation logging from warn to info

[marianosimone]

Similar to #394, these logs are a bit noisy and not that useful for the average user:

DEBUGGER:  BP - Line  /<redacted>.rb:<line> (call) is activated.

Reducing to info makes it less noisy.

[ko1]

b Foo#bar can be issued when the Foo#bar is not defined.
When Foo#bar is defined, the breakpoint is enabled.
This message is printed when the breakpoint is enabled.

The purpose of this message is BP is activated correctly.
For example, typo like b Foo#baz (typo of bar) doesn't show the activation message and you can know the typo.

I think average users need this messages.

I agree it should be info and I think default loglevel should be info.
Advanced users like you can set loglevel as a warn.

[marianosimone]

Closing in favor of #752