* Add networks tab to settings, with header.
* Adds network list to settings network tab.
* Adds form to settings networks tab and connects it to network list.
* Network tab: form adding and editing working
* Settings network form properly handles input errors
* Add translations for settings network form
* Clean up styles of settings network tab.
* Add popup-view styles and behaviour to settings network tab.
* Fix save button on settings network form
* Adds 'Add Network' button and addMode to settings networks tab
* Lint fix for settings networks tab addition
* Fix navigation in settings networks tab.
* Editing an rpcurl in networks tab does not create new network, just changes rpc of old
* Fix layout of settings tabs other than network
* Networks dropdown 'Custom Rpc' item links to networks tab in settings.
* Update settings sidebar networks subheader.
* Make networks tab buttons width consistent with input widths in extension view.
* Fix settings screen subheader height in popup view
* Fix height of add networks button in popup view
* Add optional label to chainId and symbol form labels in networks setting tab
* Style fixes for networks tab headers
* Add ability to customize block explorer used by custom rpc
* Stylistic improvements+fixes to custom rpc form.
* Hide cancel button.
* Highlight and show network form of provider by default.
* Standardize network subheader name to 'Networks'
* Update e2e tests for new settings network form
* Update unit tests for new rpcPrefs prop
* Extract blockexplorer url construction into method.
* Fix broken styles on non-network tabs in popup mode
* Fix block explorer url links for cases when provider in state has not been updated.
* Fix vertical spacing of network form
* Don't allow click of save button on network form if nothing has changed
* Ensure add network button is shown in popup view
* Lint fix for networks tab
* Fix block explorer url preference setting.
* Fix e2e tests for custom blockexplorer in account details modal changes.
* Update integration test states to include frequentRpcList property
* Fix some capitalizations in en/messages.json
* Remove some console.logs added during custom rpc form work
* Fix external account link text and url for modal and dropdown.
* Documentation, url validation, proptype required additions and lint fixes on network tab and form.
Dan J Miller