Minor improvements for ThreadX detection

[kennedyho-renesas]

This PR makes a minor change to how ThreadX is being detected.

The following table shows the before and after of the change.

Detect symbol	Before	After
_tx_thread_created_count	mandatory	mandatory
_tx_semaphore_created_count	mandatory	optional
_tx_mutex_created_count	mandatory	optional
_tx_byte_pool_created_count	mandatory	optional

Before the change, if a FW or application does not create any one of the objects (mutex, semaphore, byte pool), ThreadX will not be detected.
After the change, ThreadX can be detected, and for the tab where the object is not being created, it is shown as an empty tab as follows:

This is more of an initial improvement and can be improved further in the near future to include text indication or help, so that users know why the tab is empty.

[kennedyho-renesas]

I have updated the PR to include the following:

• Help text in empty tabs to indicate objects unavailable (not compiled or linked) or not created (0 found).
• Added number of objects indicator in each tab's title, replicating what is done in FreeRTOS.

See the following screenshots for the changes mentioned:

1. When a _tx_*_created_count symbol is missing, object not compiled/linked

2. When the object is available, but the object length is 0, none created by the user yet

3. For threads, the help message is slightly different to match what is done in FreeRTOS (similar). When debug session just started, RTOS is likely to be initialized yet, hence this is emphasized in the Threads tab.

4. Created dummy threads to check if the number of objects (length) indicator on the tab's title is accurate

[haneefdm]

Thanks @kennedyho-renesas

[raphaelmeyer]

Thanks @kennedyho-renesas for this really nice improvement!

[kennedyho-renesas]

@raphaelmeyer thank you for letting me contribute!
Just wanted to say sorry for the messy formatting. I've just learnt about the Prettier extension from your latest commit. I will be installing and using it going forward :)
Cheers!

[raphaelmeyer]

Just wanted to say sorry for the messy formatting.

No need to worry. The project is anyway not set up to enforce it.