Support DebuggerBreakOnNextLine In Hermes

[NickGerleman]

We have an instance setting, DebuggerBreakOnNextLine, which allows debugging the boot process. It is wired to Chakra and V8, but doesn't seem to effect Hermes. From feedback in teams, folks would find this functionality to be useful.

[chrisglein]

@NickGerleman Is this supported by Hermes Windows itself and we need to hook it up in RNW? Or is it also lacking in Hermes Windows (in which case we need another issue on that repo as well).

[chrisglein]

Timing here depends a lot on when the shift to Hermes as default happens. We also have gaps in postmortem debugging, for example. This one here seems pretty fundamental as well for good quality of life.

[jonthysell]

@TatianaKapos Do you think this will make 0.69 or should it be moved to 0.70?

[TatianaKapos]

@jonthysell Moved it to .70!