Amendment related pages styling updates + bugs fixes

[pdp2121]

Address the following changes to the pages:

• Align dropdown items in the NavBar to the right.
• Increase font weight for the right labels of the Amendment Summary page.
• Fix vnull issue on Amendment Summary rippled version.
• Add an ETA to indicate the time amendment would be enabled for ones that has more than 80% votes.
• Highlight color for amendments more than 80% on Amendments List page
• Reduce the font size for Yays Nays to match the top of the page.
• The y-axis of the graph should show percentage instead of count.
• Make Enabled column all caps.
• Rename Voters column to UNL Voters.
• Rename Enabled (on) to Enabled on.
• rippled version linked to rippled release for that version.
• The details link should open a new tab.
• Yays and Nays validators should link to the validator page on the Explorer.
• Capitalize the labels on Validator's Voting page.
• Fix loader timing issue on Amendments List page.
• Make Nays list magneta.
• tx column renamed to Enable tx

Optional change:

• Make a line of 80% for the graph to indicate threshold.
• Make different tabs for graph, simple, and Yays Nays for Amendment summary.
• Make the header row sticky for the list table.