Make serial connection timeout dynamic

[haslinghuis]

As a long time request this PR makes the serial reconnection timeout dynamic with a timeout of 10 seconds.
The PR makes sure we have a new connection on reinitialization and waits for the connection to be ready and fixes the bug connecting to soon with a predetermined timeout now verified by timestamp.

[ctzsnooze]

The commit does several things...

• removes the fixed 'settling time' of 0.1s that previously applied when auto-reconnecting (plugging in a board with auto-connect switch enabled)
• when a re-connect is required, eg after changing ports when a reboot is needed, the re-connection is now dynamic, taking only as long as is needed
• this removes the need for a manual re-connection time delay (which used to be set under 'Options' tab)

Here is a console log after clicking 'Save' in Ports, where it took 3.1s to reconnect

Settings Saved in EEPROM
serial_backend.js:832 Reintialising Connection
MSPHelper.js:1687 Arming disable
serial.js:249 serial: closed connection with ID: 2, Sent: 36597 bytes, Received: 463632 bytes
port_handler.js:129 PortHandler - Removed: [{"path":"/dev/cu.usbmodem0x80000001","displayName":"Betaflight STM32F411","vendorId":1155,"productId":22336},{"path":"/dev/tty.usbmodem0x80000001","displayName":"Betaflight STM32F411","vendorId":1155,"productId":22336}]
port_handler.js:169 PortHandler - Found: [{"path":"/dev/cu.usbmodem0x80000001","displayName":"Betaflight STM32F411","vendorId":1155,"productId":22336},{"path":"/dev/tty.usbmodem0x80000001","displayName":"Betaflight STM32F411","vendorId":1155,"productId":22336}]
port_handler.js:276 Porthandler detected device Betaflight STM32F411 on port: /dev/tty.usbmodem0x80000001
serial_backend.js:67 Connecting to: /dev/tty.usbmodem0x80000001
serial.js:119 serial: connection opened with ID: 3 , Baud: 115200
serial_backend.js:246 Requesting configuration data
serial_backend.js:849 Serial connection available after 3.1 seconds

Tested, works well.

[asizon]

Seems a new improvement not a bug fix, weneed to release 10.8.0 this year

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[github-actions]

Do you want to test this code? Here you have an automated build:
Betaflight-Configurator-Debug-Android
Betaflight-Configurator-Debug-Linux
Betaflight-Configurator-Debug-macOS
Betaflight-Configurator-Debug-Windows
WARNING: It may be unstable and result in corrupted configurations or data loss. Use only for testing!

[blckmn]

AUTOMERGE: (FAIL)

• github identifies PR as mergeable -> FAIL
• assigned to a milestone -> PASS
• cooling off period lapsed -> PASS
• commit count less or equal to three -> PASS
• Don't merge label NOT found -> PASS
• at least one RN: label found -> PASS
• Tested label found -> PASS
• assigned to an approver -> PASS
• approver count at least three -> FAIL