Name sanitation behavior changed between Chisel v3.3 and v3.4

From https://github.com/chipsalliance/chisel3/pull/1624#issuecomment-711415026

**Type of issue**: bug report

**Impact**: no functional change | API addition (no impact on existing code) | API modification | unknown

**Development Phase**: request | proposal

**Other information**

**If the current behavior is a bug, please provide the steps to reproduce the problem:**

```scala
class MyBundle extends Bundle {
val foo = UInt(8.W)
val `foo😎` = UInt(8.W)
val `foo😎😎` = UInt(8.W)
}

class Example extends MultiIOModule {
val in = IO(Input(new MyBundle))
val out = IO(Output(new MyBundle))

out := in
}
```

**What is the current behavior?**

In v3.4.2 gives:
```verilog
module Example(
input clock,
input reset,
input [7:0] in_foo,
output [7:0] out_foo
);
assign out_foo = in_foo; // @[main.scala 16:7]
endmodule
```
https://scastie.scala-lang.org/TcWA1dnGSEyfNeqOSM9i5g

**What is the expected behavior?**

In v3.3.3 this gives
```verilog
module Example(
input clock,
input reset,
input [7:0] in_foo,
input [7:0] in_foouD83DuDE0E,
input [7:0] in_foouD83DuDE0EuD83DuDE0E,
output [7:0] out_foo,
output [7:0] out_foouD83DuDE0E,
output [7:0] out_foouD83DuDE0EuD83DuDE0E
);
assign out_foo = in_foo; // @[main.scala 16:7]
assign out_foouD83DuDE0E = in_foouD83DuDE0E; // @[main.scala 16:7]
assign out_foouD83DuDE0EuD83DuDE0E = in_foouD83DuDE0EuD83DuDE0E; // @[main.scala 16:7]
endmodule
```
https://scastie.scala-lang.org/f43qpaw6SYCaA2Gg9mXPXg

I'm not going to argue those names are better, in fact, perhaps `v3.4.2` is better, but the fact that the ports collide down to one is problematic.

**What is the use case for changing the behavior?**

Don't have ports disappear randomly and gracefully handle unicode names.

Start with the Scala reproducer in the issue and compare generated Verilog from Chisel v3.3.3 and v3.4.2, focusing on name sanitation for Unicode field names. The fix should prevent distinct ports such as foo😎 and foo😎😎 from disappearing or colliding, while preserving graceful Unicode handling.

Written by the indexing model from the issue text.