feat(tx-builder): Add dark mode support

[clovisdasilvaneto]

What it solves

Resolves #824

How this PR fixes it

It adds dark mode theme palette into the project and set the theme based on the postMessage event which we receive from the safe wallet app.

How to test it

• Go to your safe at this link: https://feat_tx_builder_dark_mode--walletweb.review.5afe.dev/home?safe=eth:0xA77DE01e157f9f57C7c4A326eeE9C4874D0598b6 (or by using this branch from the safe wallet repo: feat/tx-builder-dark-mode)
• Take the deploy link on this PR and add it as a custom safe app on your safe
• Open the custom tx-builder app which you just added
• Change the dark mode toggle on the sidebar
• The transaction builder theme should change according to safe wallet theme

Video

txbuilder.webm

[github-actions]

• Drain Account App
• RAMP Network App
• Sign-In With Ethereum Delegate Manager App
• Tx Builder App
• WalletConnect app
• MMI App

[francovenica]

Issues:

1 - The form when you edit a tx that is batched on the right side is still white:

2 - The list of saved batches show the list of them white as well:
For this you must save it in the library first:

Go to Your tx library:

And then you see this:

[clovisdasilvaneto]

@francovenica thanks! I'll take a look on them

[clovisdasilvaneto]

@francovenica done ✅ Can you please check that again? Please make sure to clear your cache  😉

[francovenica]

I think the fixes broke some stuff in light mode now:

The saved batches, there is a number that should be white
There is a gray background that should be white

Same in the tx edition:
For the light mode there is a gray background when in dev is fully white. A comparison here:

in dev:

Also in the dark mode I think the whole modal should be gray. Compare it with any other tx in the site:

The tx edition in the tx builder:

A regular tx color:

[clovisdasilvaneto]

@francovenica can you please check that again?

[francovenica]

All the issues fixed
LGTM now.