Wifi update fixes

[pkendall64]

Problem 1

Uploading long named files caused "File not found" errors. This is because SPIFFS only allows 31 char filenames.

Solution 1

Ignore the name passed in on upload for the name on the SPIFFS partition and use a hard-coded name.

Problem 2

Uploading STM firmware via the backpack in AP mode would finish with "Update Failed" and no other information, implying that the network had gone away, i.e. the ESP was rebooted.

Solution 2

Why reboot the ESP when completing the STM update? Don't do that.

Test Plan

Windows STA Mode

Action	Expectation	Status
Update "backpack" from RX to TXBP	Should show upload progress, then popup mismatch dialog	✅
	Click "Cancel" should abort	✅
	Click "Flash anyway" should show flashing progress, display "Success" dialog and update to TXBP firmware	✅
Update "backpack" from TXBP to TXBP	Should show upload and flashing progress, then display "Success" dialog	✅
Update "TX" firmware using .elrs file	Should show upload and flashing progress, then display "Success" dialog	✅

Windows AP Mode

Action	Expectation	Status
Update "backpack" from RX to TXBP	Should show upload progress, then popup mismatch dialog	✅
	Click "Cancel" should abort	✅
	Click "Flash anyway" should show flashing progress, display "Success" dialog and update to TXBP firmware	✅
Update "backpack" from TXBP to TXBP	Should show upload and flashing progress, then display "Success" dialog	✅
Update "TX" firmware using .elrs file	Should show upload and flashing progress, then display "Success" dialog	✅

Mac STA Mode

Action	Expectation	Status
Update "backpack" from RX to TXBP	Should show upload progress, then popup mismatch dialog	✅
	Click "Cancel" should abort	✅
	Click "Flash anyway" should show flashing progress, display "Success" dialog and update to TXBP firmware	✅
Update "backpack" from TXBP to TXBP	Should show upload and flashing progress, then display "Success" dialog	✅
Update "TX" firmware using .elrs file	Should show upload and flashing progress, then display "Success" dialog	✅

Mac AP Mode

Action	Expectation	Status
Update "backpack" from RX to TXBP	Should show upload progress, then popup mismatch dialog	✅
	Click "Cancel" should abort	✅
	Click "Flash anyway" should show flashing progress, display "Success" dialog and update to TXBP firmware	✅
Update "backpack" from TXBP to TXBP	Should show upload and flashing progress, then display "Success" dialog	✅
Update "TX" firmware using .elrs file	Should show upload and flashing progress, then display "Success" dialog	✅