Make sure all inspection exception are gracefully handled

[st0012]

Currently, if we evaluate an object with issue in its #inspect method, it'll crash the debugger:

(rdbg) foo
["DEBUGGER Exception: /Users/st0012/projects/debug/lib/debug/thread_client.rb:970",
 #<RuntimeError: foo>,
 ["target.rb:4:in `inspect'",
  "/Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/pp.rb:304:in `pretty_print'",
  "/Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/pp.rb:177:in `block in pp'",
  "/Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/prettyprint.rb:253:in `block (2 levels) in group'",
  "/Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/prettyprint.rb:280:in `nest'",
  "/Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/prettyprint.rb:252:in `block in group'",
  "/Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/prettyprint.rb:265:in `group_sub'",
  "/Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/prettyprint.rb:251:in `group'",
  "/Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/pp.rb:177:in `pp'",
  "/Users/st0012/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/irb-1.3.7/lib/irb/color_printer.rb:29:in `pp'",
  "/Users/st0012/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/irb-1.3.7/lib/irb/color_printer.rb:10:in `block in pp'",
  "/Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/pp.rb:134:in `guard_inspect_key'",
  "/Users/st0012/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/irb-1.3.7/lib/irb/color_printer.rb:10:in `pp'",
  "/Users/st0012/projects/debug/lib/debug/color.rb:52:in `color_pp'",
  "/Users/st0012/projects/debug/lib/debug/thread_client.rb:781:in `wait_next_action_'",
  "/Users/st0012/projects/debug/lib/debug/thread_client.rb:660:in `wait_next_action'",
  "/Users/st0012/projects/debug/lib/debug/thread_client.rb:280:in `suspend'",
  "/Users/st0012/projects/debug/lib/debug/thread_client.rb:218:in `on_breakpoint'",
  "/Users/st0012/projects/debug/lib/debug/breakpoint.rb:63:in `suspend'",
  "/Users/st0012/projects/debug/lib/debug/breakpoint.rb:147:in `block in setup'",
  "/Users/st0012/projects/debug/lib/debug/session.rb:2157:in `debugger'",
  "target.rb:33:in `<main>'"]]
target.rb:4:in `inspect': foo (RuntimeError)
        from /Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/pp.rb:304:in `pretty_print'
        from /Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/pp.rb:177:in `block in pp'
        from /Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/prettyprint.rb:253:in `block (2 levels) in group'
        from /Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/prettyprint.rb:280:in `nest'
        from /Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/prettyprint.rb:252:in `block in group'
        from /Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/prettyprint.rb:265:in `group_sub'
        from /Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/prettyprint.rb:251:in `group'
        from /Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/pp.rb:177:in `pp'
        from /Users/st0012/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/irb-1.3.7/lib/irb/color_printer.rb:29:in `pp'
        from /Users/st0012/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/irb-1.3.7/lib/irb/color_printer.rb:10:in `block in pp'
        from /Users/st0012/.rbenv/versions/3.0.2/lib/ruby/3.0.0/pp.rb:134:in `guard_inspect_key'
        from /Users/st0012/.rbenv/versions/3.0.2/lib/ruby/gems/3.0.0/gems/irb-1.3.7/lib/irb/color_printer.rb:10:in `pp'
        from /Users/st0012/projects/debug/lib/debug/color.rb:52:in `color_pp'
        from /Users/st0012/projects/debug/lib/debug/thread_client.rb:781:in `wait_next_action_'
        from /Users/st0012/projects/debug/lib/debug/thread_client.rb:660:in `wait_next_action'
        from /Users/st0012/projects/debug/lib/debug/thread_client.rb:280:in `suspend'
        from /Users/st0012/projects/debug/lib/debug/thread_client.rb:218:in `on_breakpoint'
        from /Users/st0012/projects/debug/lib/debug/breakpoint.rb:63:in `suspend'
        from /Users/st0012/projects/debug/lib/debug/breakpoint.rb:147:in `block in setup'
        from /Users/st0012/projects/debug/lib/debug/session.rb:2157:in `debugger'
        from target.rb:33:in `<main>'

This PR fixes the issue:

(rdbg) foo
#<RuntimeError: foo> rescued during inspection
(rdbg)