Make public addresses representation consistent throughout the application

**User Story**
As a user, I want public addresses to be represented the same way everywhere (including mobile and extension) so that I don't get confuse when comparing it.

Currently we show full and truncated versions of public address in many screens of the extension and mobile, but in some they appear as all small letters while in others they appear with capital and small letters (checksummed version). This causes confusion to new users that are not sure if both representations are the same.

[User story on Notion](https://www.notion.so/As-a-user-I-want-public-addresses-to-be-represented-the-same-way-on-everywhere-including-on-mobile-970c6af57d39489582ceb6276620f849)
[Designs on Figma](https://www.figma.com/file/b1YjR0OG4RRQgEChYfwbey/UI-audit?node-id=0%3A1)

**Steps to reproduce**
1. Go to the initial screen and see your truncated address with capital and small letters (checksummed version)
2. Click "Send"
3. Click "Transfer between my accounts" and see the truncated addresses with all small letters
4. Choose an account from the list and see the the full address with all small letters

**Screenshots**
Initial screen:

Send screen:

**Task**
Implementing a standard for capital vs small letter public address representation throughout the extension. The recommended format is the checksummed version - [Notion link](https://www.notion.so/As-a-user-I-want-public-addresses-to-be-represented-the-same-way-on-everywhere-including-on-mobile-970c6af57d39489582ceb6276620f849?d=1dd8238c219e408aaf9e59c15cd5cec8) .

**Success criteria**
Having a consistent representation (checksummed version vs all small letters) of public address throughout the extension