Fix token refresh error

[louise-davies]

Description

Goes with ral-facilities/datagateway#1262

Allow plugins to send a notification payload alongside their token invalidation request event, which we then only display after the token refresh has failed.

Testing instructions

• Review code
• Check Actions build
• Review changes to test coverage
• Get me to lower the ICAT session length (or mock that yourself) and test with PR Bugfix/fix token refresh error #1257 datagateway#1262

Agile board tracking

Part of the fix for ral-facilities/datagateway#1257

[codecov]

Codecov Report

Merging #1072 (17d8a69) into develop (4660cc7) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop    #1072      +/-   ##
===========================================
+ Coverage    97.93%   97.94%   +0.01%     
===========================================
  Files           42       42              
  Lines         1551     1560       +9     
  Branches       417      418       +1     
===========================================
+ Hits          1519     1528       +9     
  Misses          31       31              
  Partials         1        1              

Impacted Files	Coverage Δ
src/state/middleware/scigateway.middleware.tsx	93.23% <100.00%> (+0.49%)	⬆️

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