Replace `.pf*` with C equivalent and fix `tc` tests.

[wargio]

Due the changes in #5540 several tests in test/db/cmd/cmd_tc have been marked as broken due pf not producing anymore valid commands to apply flags at a given offset.

Before that PR, you could call pf* to generate all the needed commands to define the structure manually and with the help of . (i.e. eval) you could do .pf* foo @ 0x1234 to define the structure foo at address 0x1234.

The idea is a similar command from the pf command group to define the structure at the current offset, so the user could do pf<new cmd> @ 0x1234 to achieve the same thing.

See librz/type/format.c code for more details.

[Eshaan-byte]

I'd like to work on this issue. I'll:

1. Review the changes in #5540 to understand what broke
2. Implement a new pf command to define structures at the current offset
3. Update the broken tests in test/db/cmd/cmd_tc to use the new command
4. Ensure the new implementation provides equivalent functionality to the old pf

Could you assign this to me?

[notxvilka]

Could you assign this to me?

Just send a PR. We will not assign until then.