Reject non-minimal Bitcoin CompactSize encodings

[SashaMIT]

Summary

decode() accepted a longer tag for a value that fits in a shorter one. fd0100, fe01000000, and ff0100000000000000 all decoded as 1. Bitcoin CompactSize rejects that. A 0xfd value must be at least 0xfd, a 0xfe value must be greater than 0xffff, and a 0xff value must be greater than 0xffffffff.

Test plan

• Before the change those three buffers decoded as { numberValue: 1, bytes: 3|5|9 }
• They now throw non-minimal encoding
• npx tape test/*.js (92 tests OK), including the existing minimal vectors such as fdfd00

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