Rename SanitizedMessage::try_from to try_from_legacy_message

[jstarry]

Problem

TryFrom only supports a single argument, but in #34901, SanitizedMessage will need an additional parameter for reserved account keys.

Summary of Changes

Rename SanitizedMessage::try_from to try_from_legacy_message

Note that the only non test/bench uses of the changed method are in banks-server and banks-client

Fixes #

[codecov]

Codecov Report

Attention: Patch coverage is 99.13793% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 81.7%. Comparing base (da08868) to head (d58b00c).
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##           master   #35338     +/-   ##
=========================================
- Coverage    81.7%    81.7%   -0.1%     
=========================================
  Files         834      834             
  Lines      224244   224309     +65     
=========================================
- Hits       183398   183392      -6     
- Misses      40846    40917     +71