Squashed 'external/devlib/' changes from ab193ed41..e1407127e

e1407127e ftrace: Add write-to-disk mode
81674b046 connection: Support all signals in BackgroundCommand.send_signal()
1c1e860e9 utils/asyn: Ensure the async generators inside context managers are fully consumed on a single event loop
9cab4713c utils/asyn: Replace nest_asyncio with greenlet
7e0e7442c Revert "utils/asyn: Replace nest_asyncio with greenback"
c9178d20a utils/asyn: Replace nest_asyncio with greenback
22df0fb7c utils/asyn: Factor out the calls to asyncio.run
02f030936 target: Allow reuse of a connection once the owning thread is terminated
a5d2411e9 tests: Add tests for nested async support
REVERT: ab193ed41 utils/asyn: Ensure the async generators inside context managers are fully consumed on a single event loop
REVERT: b2c7bb9b0 utils/asyn: Replace nest_asyncio with greenlet
REVERT: 5ff1d543a Revert "utils/asyn: Replace nest_asyncio with greenback"
REVERT: 4cf7d1856 utils/asyn: Replace nest_asyncio with greenback
REVERT: 03521493d utils/asyn: Factor out the calls to asyncio.run
REVERT: 5aa850ec9 target: Allow reuse of a connection once the owning thread is terminated
REVERT: a9a2d75c4 tests: Add tests for nested async support

git-subtree-dir: external/devlib
git-subtree-split: e1407127e6ce4485dbf26d03e5850758d7334971