fix: deprecate wallet.near.org & explorer.near.org

[thisisjoshford]

Fixes #418

As wallet.near.org & explorer.near.org are no longer active, this PR updates these urls to active projects (app.mynearwallet.com & nearblocks.io)

[frol]

Consider keeping explorer.near.org - it is a selector of all the available Explorers, instead of hardcoding one specific Explorer there.

[thisisjoshford]

Consider keeping explorer.near.org - it is a selector of all the available Explorers, instead of hardcoding one specific Explorer there.

Are you suggesting we send them to the explorer landing site and then tell them to choose one and search for this tx? or should we have both a direct link to tx and the general landing page for visibility on other options they have?

I particularly like having a smooth UX of a one click to tx result, but I see your point in not forcing one solution over another. If we wanted to be super slick we could have the user choose which explorer they would want to use and then it saves this configuration for future CLI transactions :)