Asynchronous file loading for search task

[nbollis]

Changed the loading of MsDataFiles, Proteins, Spectral Libraries, and Modifications to asynchronous methods within search task.

This enables a file to loading in the background and the main thread to continue execution.
Wait handlers were added to ensure the files are loaded before they are needed by the rest of the code.

The main meat of this PR is that we are now loading the next MsDataFile to be searched, while the previous one is being searched.

MM 1.0.5 and this PR were ran side by side for a
47 raw file top down search:

• 1.0.5 time -> 1:20:56
• This PR time -> 1:01:47

20 mzml file top down search:

• 1.0.5 time -> 3:40:56
• This PR time -> 2:59:23

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.90%. Comparing base (93b672e) to head (9620228).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2381   +/-   ##
=======================================
  Coverage   92.89%   92.90%           
=======================================
  Files         139      139           
  Lines       21435    21461   +26     
  Branches     2944     2948    +4     
=======================================
+ Hits        19913    19939   +26     
  Misses       1043     1043           
  Partials      479      479           

Files	Coverage Δ
MetaMorpheus/TaskLayer/SearchTask/SearchTask.cs	95.83% <100.00%> (+0.28%)	⬆️

[elaboy]

great optimization Nic