[TextField] Implement variant without shrinking label

[eoliphan]

This isn't standard Material UI, but the spec's handling of input labels is perhaps one of its most loved and hated bits. Labels outside is a pretty common pattern, so would be nice to just have a variant for it, to avoid losing the convenience of the high-level TextField, etc abstraction

• I have searched the issues of this repository and believe that this is not a duplicate.

Summary 💡

Basically something like <TextField variant="normal"/> would render

<FormControl ..>
   <InputLabel> ...  // perhaps a bit larger/bolder than the MUI default, no shrink
   <OutlinedInput> ..
   <FormHelperText>..
   ...   

Basically something sort of like the bootstrap input styling example

Motivation 🔦

Ease of use for a non-spec, but common pattern for fields and their input labels

[siriwatknp]

cc @michaldudak may be unstyled can provide a composition for this.

[michaldudak]

With the unstyled TextField you'll be able to implement various patterns regarding inputs and labels, but it will require customization. Perhaps the second design system that we about to work on could have a solution. As far as I remember we were discussing not having labels inside (visually) inputs.