Add empty state to Portfolio when filters are applied

[StephenHeaps]

Description

Add an empty state to Portfolio when no assets are displayed. This can occur with a combination of the Group By and deselecting all accounts / networks.

Discussion:
https://bravesoftware.slack.com/archives/C023VS4HJ6Q/p1686939237810999

Steps to Reproduce

1. Open Portfolio and tap the filters button
2. In Filters and display settings, set Group by to None or Networks
3. Deselect all networks
4. Tap save changes
5. Observe no assets show, no empty state
6. Tap the filters button in Portfolio
7. In Filters and display settings, set Group by to Accounts
8. Deselect all accounts
9. Tap save changes
10. Observe no assets show, no empty state

Actual result:

Expected result:

Empty state tbd

Reproduces how often:

Easily reproduced

Brave version (brave://version info)

Version 1.54.70 Chromium: 114.0.5735.133 (Official Build) nightly (arm64)

Version/Channel Information:

• Can you reproduce this issue with the current release?
• Can you reproduce this issue with the beta channel?
• Can you reproduce this issue with the nightly channel?

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields?
• Does the issue resolve itself when disabling Brave Rewards?
• Is the issue reproducible on the latest version of Chrome?

Miscellaneous Information:

[srirambv]

Verification passed on

Brave	1.58.114 Chromium: 116.0.5845.163 (Official Build) beta (64-bit)
Revision	21631edab5a70964c2f5817bfa4d06c32b4ab314
OS	Linux

• Verified steps from brave/brave-core#19308
• Verified Empty Token List is shown when all network/accounts is disabled in Portfolio settings
• Verified other call to actions (Buy/Send/Swap/Market) work as expected

31147.mp4

---

Verification passed on

Brave	1.58.114 Chromium: 116.0.5845.163 (Official Build)) beta (64-bit)
Revision	21631edab5a70964c2f5817bfa4d06c32b4ab314
OS	Windows 11 Version 22H2 (Build 22621.2215)

• Verified steps from brave/brave-core#19308
• Verified Empty Token List is shown when all network/accounts is disabled in Portfolio settings
• Verified other call to actions (Buy/Send/Swap/Market) work as expected

31147.mp4

---

Verification passed on

Brave	1.58.114 Chromium: 116.0.5845.163 (Official Build) beta (arm64)
Revision	21631edab5a70964c2f5817bfa4d06c32b4ab314
OS	macOS Version 13.4.1 (c) (Build 22F770820d)

• Verified steps from brave/brave-core#19308
• Verified Empty Token List is shown when all network/accounts is disabled in Portfolio settings
• Verified other call to actions (Buy/Send/Swap/Market) work as expected

31147.mov