[lldb] Inline expression evaluator error visualization (#106470)

This patch is a reworking of Pete Lawrence's (@PortalPete) proposal
for better expression evaluator error messages:
https://github.com/llvm/llvm-project/pull/80938

Before:

```
$ lldb -o "expr a+b"
(lldb) expr a+b
error: <user expression 0>:1:1: use of undeclared identifier 'a'
a+b
^
error: <user expression 0>:1:3: use of undeclared identifier 'b'
a+b
  ^
```

After:

```
(lldb) expr a+b
            ^ ^
            │ ╰─ error: use of undeclared identifier 'b'
            ╰─ error: use of undeclared identifier 'a'
```

This eliminates the confusing `<user expression 0>:1:3` source
location and avoids echoing the expression to the console again, which
results in a cleaner presentation that makes it easier to grasp what's
going on. You can't see it here, bug the word "error" is now also in
color, if so desired.

Depends on https://github.com/llvm/llvm-project/pull/106442.