Add background color to progress bar when flashing firmware

[tituscmd]

This PR adds a background color to the progress bar when updating firmware.
It also removes the space between the value and the "%", since I feel like that's more commonly used and, in my opinion, looks better. Feel free to give your opinion on that, though!

Here's a pic of how it looks like on device:
(Hint: To see it in action, you’ll first need to flash the firmware. Then, flash any other firmware, as the firmware update screen is displayed by the firmware currently on the device.)

[github-actions]

Build size and comparison to main:

Section	Size	Difference
text	373152B	32B
data	948B	0B
bss	22536B	0B

Run in InfiniEmu

[mark9064]

Haven't tested on HW, but looks good from the screenshot :)

[Saarsk]

Just a note about the space between the value and percentage sign. A space there is the correct way of writing it. 🙂 I think it should be formatted the correct way.

I can understand that sometimes it happens that the correct way doesn't feel right. We tend to expect what we're conditioned to. I've had the same experience.

Though, it's just a matter of getting used to it, i.e. reconditioning. So rather than doing what subjectively feels right I think there's value to following objectively correct and commonly agreed conventions. 🙂 A lack there of will have negative effects regardless whether it's in a software project or in a book, as we adopt by reading and using language. So whenever something is incorrect, it spreads.

Other than that, I very much welcome the progress bar improvement. 😊

[tituscmd]

"However, the International System of Units and ISO 31-0 standard prescribe a space between the number and percent sign,[8][9][10] in line with the general practice of using a non-breaking space between a numerical value and its corresponding unit of measurement."

Let's go for this then, shall we?

[mark9064]

I think without the space is better. Wikipedia is quite clear: English style guides prescribe writing the percent sign following the number without any space between (e.g. 50%)

InfiniTime is not a technical document, but instead a user interface. Therefore I think following general English style and precedent makes sense. If it were a technical report then I would agree that recognising a standard such as ISO would be sensible (and if I were typsetting with LateX I would by using siunitx), and the same may apply in another language (it appears that some languages expect a space by default)