The unmap command followed by a comment is ignored

Describe the bug

When the unmap command in the custom key mappings is followed by a comment, it's ignored and doesn't have any effect. The map command doesn't have such an issue.

To Reproduce

1. Add the following commands to the Vimium's custom key mappings and save them:

    map A Vomnibar.activate  # test
    unmap A  # test
   

2. Open the Vimuim's help and check the first command under the Using the vomnibar section (top right column) - it has the A key assigned even though it should be unmapped

3. Remove the comment after the unmap A command in the custom key mappings and save them:

    map A Vomnibar.activate  # test
    unmap A
   

4. Open the Vimuim's help and check the first command under the Using the vomnibar section (top right column) - the A key is not assigned as expected, because it has been unmapped

Browser and Vimium version

Vivaldi 4.0.2312.27 64-bit (Chromium 91.0.4472.102)
Wavebox 10.0.542.2 (Chromium 91.0.4472.77)
Vimium 1.66

Start by tracing how custom key mappings parse the map and unmap commands, especially trailing comments, then follow how the mappings appear in Vimium's help. Reproduce the two mapping examples from the issue and verify that a commented unmap A removes the A assignment just like an uncommented command.