fix: retrieving public key from wallet for bond transactions

[b00f]

Description

This PR includes several changes:

• Made the public key for the Bond transaction optional.
• Obtained the validator's public key from the wallet.
• Checked if the validator exists and removed the public key before signing and broadcasting the Bond transaction.
• Added a hint string for the receiver in the Bond and Send transactions within the GUI.
• Modify the display of amounts to show them without trailing zeros.

Overall, this PR aims to simplify the Bond transaction dialog and enhance the user experience for easily sending Bond transactions.

[codecov]

Codecov Report

Merging #485 (4a0de7e) into main (aa8b886) will increase coverage by 0.03%.
The diff coverage is 100.00%.

❗ Current head 4a0de7e differs from pull request most recent head 08071dc. Consider uploading reports for the commit 08071dc to get more accurate results

@@            Coverage Diff             @@
##             main     #485      +/-   ##
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+ Coverage   82.44%   82.48%   +0.03%     
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  Files         150      150              
  Lines        7059     7069      +10     
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+ Hits         5820     5831      +11     
+ Misses        945      944       -1     
  Partials      294      294