Merge #20162: p2p: declare Announcement::m_state as uint8_t, add getter/setter

c8abbc9d1fd8f77b5dcf31cf7a6dd6aac5d1c75c p2p: declare Announcement::m_state as uint8_t, add getter/setter (Jon Atack)

Pull request description:

  Change `Announcement::m_state` in `tx_request.cpp` from type `State` to `uint8_t` and add a getter and setter for the conversion to/from `State`. This should silence these travis ci gcc compiler warnings:

  ```
  txrequest.cpp:73:21: warning: ‘{anonymous}::Announcement::m_state’ is
  too small to hold all values of ‘enum class {anonymous}::State’
       State m_state : 3;
                       ^
  ```

  The gcc warnings are based on the maximum value held by the underlying uint8_t enumerator type, even though the intention of the bitfield declaration is the maximum declared enumerator value. They have apparently been silenced in gcc 8.4+ and 9.3+ according to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61414.

ACKs for top commit:
  sipa:
    utACK c8abbc9d1fd8f77b5dcf31cf7a6dd6aac5d1c75c
  ajtowns:
    ACK c8abbc9d1fd8f77b5dcf31cf7a6dd6aac5d1c75c -- quick code review
  hebasto:
    ACK c8abbc9d1fd8f77b5dcf31cf7a6dd6aac5d1c75c, tested on Bionic (x86_64, gcc 7.5.0):

Tree-SHA512: 026721dd7a78983a72da77638d3327d2b252bef804e489278a852f000046c028d6557bbd6c2b4cea391d4e01f9264a1be842d502047cb90b2997cc37bee59e61

0 files changed, 0 insertions, 0 deletions