avoid using redirect function

[clelange]

function: https://github.com/clelange/PixelTCDSSupervisor/blob/master/src/common/PixelTCDSSupervisor.cc#L850-861

is called every time you click a link on the mainPage. This should be turned into GET requests instead to remain on the same page.

[clelange]

When you use expert actions tab, and hit send, you should remain on the page, i.e. use javascript to submit the content (post) and do not redirect to blank page.

[clelange]

works for "Load new hardware configuration file (from disk accessible from XDAQ application)", needs to be done for others