[MPQEditor] Make layout more user-friendly

[stamalakhov]

What?

Let's make MPQEditor layout more user- friendly.

Why?

See original discussion in #1539 (comment).

[stamalakhov]

@dayo09 @seanshpark
Initial draft is proposed at #1542.
Otherwise we can try to make both sections collapsible as was done at metadataviewer .
Or/and we can add ? button for both sections.

[dayo09]

+ @jinevening

For other reviewers, to summarize:
I suggested adding 'default configuration' or 'per-layer configuration' title to each area as below.

          Hi, this is another UI feedback.

It's not related to this PR, but rather related to the draft #1505.

It seems that : In the (1) area, it decides the default quantization configuration and (2) area specifies the per-node(layer) quantization configuration.

At first look, I didn't understand what the (1) area would do. From my point of view, I propose to add 'Set default quantization' 'Set specific layer's quantization' in each areas.

Originally posted by @dayo09 in #1539 (comment)

[dayo09]

I just got another idea - how about adding 'default' just as the same as the other layers? Not as a radio button, but just as a drop box element just the same as other layers. Therefore we don't need to put some text information.

[stamalakhov]

I just got another idea - how about adding 'default' just as the same as the other layers? Not as a radio button, but just as a drop box element just the same as other layers. Therefore we don't need to put some text information.

@dayo09

1. Like this?:
   

2. or ?:
   

3. Or something different?

[dayo09]

I meant 1.) 😄

[stamalakhov]

I meant 1.) 😄

Ahh. Ok. Thank you!