[FEATURE] Add JSON Datasource and Json Query plugin

[adrianSepiol]

Related issue: perses/perses#3284
Depends on:

• [FEATURE] Add JsonQuery support shared#230
• [FEATURE] Add JsonData query type spec#70

Description

Adds json datasource and query plugin. It allows to query any endpoint that returns json and optionally parse output with jsonata. This MVP allows for:

• querying data with GET
• querying data with post with json body
• adding query params
• using variables in path, body and request params
• using result with Table plugin

Limitations:

• using variables in jsonata expression is not allowed as it conflicts with its syntax
• only json body is allowed for post call

Screenshots

Datasource editor:

Query plugin for GET:

Query Plugin for POST:

Query with request params:

Query with body:

Error for empty response:

Checklist

• Pull request has a descriptive title and context useful to a reviewer.
• Pull request title follows the [<catalog_entry>] <commit message> naming convention using one of the
  following catalog_entry values: FEATURE, ENHANCEMENT, BUGFIX, BREAKINGCHANGE, DOC,IGNORE.
• All commits have DCO signoffs.

UI Changes

• Changes that impact the UI include screenshots and/or screencasts of the relevant changes.
• Code follows the UI guidelines.