Configuring middleware in the component

[hhunter-ms]

Description

New doc for configuring middleware Add new middleware node under 'Developing Applications/Components"

Issue reference

PR will close: #3917

[sadath-12]

Thanks for the pr @hhunter-ms . left some comments

[sadath-12]

consider also adding these points --

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We are adding 2 new metadata options (all keys and values are handled as case-insensitive): pipeline can be set to httpPipeline or appHttpPipeline (we'll have aliases including http-pipeline and http for the first; app-http-pipeline and app for the second) priority is an integer from -MaxInt32 to +MaxInt32 Both metadata options are required for the component to be enabled in a pipeline. For backwards-compatibility, there's no default priority.

Components with lower priorities are executed first Priorities don't necessarily need to be sequential. In the docs, we will document as best practice the use of values like "100", "200", "300", etc - so changing the order is less complex

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just pasting it from the design issue. you can re-fashion it