[VM/values/custom/vregex] show error if RegEx creation fails

[github-actions]

right now, if there is an error in the regex, the program

just crashes

For example:

```

to :regex "\w: (?\d+), \w: (?\d+)"

```

arturo/src/vm/values/custom/vregex.nim

Line 65 in 4876185

# TODO(VM/values/custom/vregex) show error if RegEx creation fails

    else:
        rx.pattern

# TODO(VM/values/custom/vregex) show error if RegEx creation fails
#  right now, if there is an error in the regex, the program
#  just crashes
#
#  For example:
#   ```
#   to :regex "\w: (?\d+), \w: (?\d+)"
#   ```
#  labels: values, :regex, error handling

proc newRegexObj*(pattern: string, flags: string = ""): VRegex =
    when defined(WEB):
        if flags == "":