Add "[J]ump to path" command, to support dropping out to inspect values

[NHDaly]

This allows quitting an inspection and easily returning later.

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Select a field to recurse into or ↩ to ascend. [q]uit.

Commands: [J]ump to field path.

(d)::Dict{Any,Int64} => 464.0 B
   64.0 B internal
3 Allocated Fields:
 → keys::Array{Any,1} => 176.0 B
   vals::Array{Int64,1} => 168.0 B
   slots::Array{UInt8,1} => 56.0 B
   ↩
Enter the complete path to jump to (e.g. `parent.arr[2].keys[2].foo.bar`):
Path: d.keys[6]
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Select a field to recurse into or ↩ to ascend. [q]uit.

Commands: [J]ump to field path.

(d.keys[6])::Int64 => 8.0 B
0 Allocated Fields:
 → ↩