[CBW-1076] Fix manage lookup

[shjortConcordium]

Purpose

Fix not blocking lookfornew view for invalid tokens.

Changes

• Restructure load of token metadata so that it can be awaited.
• Verify checksum of metadata.

Checklist

• [x] My code follows the style of this project.
• [x] The code compiles without warnings.
• [x] I have performed a self-review of the changes.
• [x] I have documented my code, in particular the intent of the hard-to-understand areas.
• [x] (If necessary) I have updated the CHANGELOG.

[github-actions[bot]]

File	Coverage [0%]	:x:
ProxyRepository.kt	0%	:x:
MetadataApiInstance.kt	0%	:x:
TokensAddAdapter.kt	0%	:x:
TokensViewModel.kt	0%	:x:
ContractAddressFragment.kt	0%	:x:
LookForNewTokensFragment.kt	0%	:x:
ProxyBackend.kt	0%	:x:

Total Project Coverage	0.91%	:x:

[github-actions[bot]]

File	Coverage [0%]	:x:
EncodingUtil.kt	0%	:x:
HashUtil.kt	0%	:x:
ProxyRepository.kt	0%	:x:
MetadataApiInstance.kt	0%	:x:
TokensAddAdapter.kt	0%	:x:
TokensViewModel.kt	0%	:x:
ContractAddressFragment.kt	0%	:x:
LookForNewTokensFragment.kt	0%	:x:
ProxyBackend.kt	0%	:x:

Total Project Coverage	0.91%	:x:

[github-actions[bot]]

File	Coverage [0.34%]	:x:
HashUtil.kt	100%	:green_apple:
ProxyRepository.kt	0%	:x:
MetadataApiInstance.kt	0%	:x:
TokensAddAdapter.kt	0%	:x:
TokensViewModel.kt	0%	:x:
ContractAddressFragment.kt	0%	:x:
LookForNewTokensFragment.kt	0%	:x:
ProxyBackend.kt	0%	:x:

Total Project Coverage	0.95%	:x:

[github-actions[bot]]

File	Coverage [0.34%]	:x:
HashUtil.kt	100%	:green_apple:
ProxyRepository.kt	0%	:x:
MetadataApiInstance.kt	0%	:x:
TokensAddAdapter.kt	0%	:x:
TokensViewModel.kt	0%	:x:
ContractAddressFragment.kt	0%	:x:
LookForNewTokensFragment.kt	0%	:x:
ProxyBackend.kt	0%	:x:

Total Project Coverage	0.95%	:x: