Add SAST inline findings

What does this MR do and why?

This MR solves: #384989 (closed)
It introduces the first Iteration of displaying Sast findings inline in the Merge Request diff.

Screenshots or screen recordings

before	after
2023-05-05_10-47-11	2023-05-03_16-04-28

How to set up and validate locally

Sast Findings

1. Clone this project into your GDK
2. Recreate this 1-liner MR jannik_lehmann/sast-inline-findings-example!1 (merged)
3. See the SAST inline Findings in Action

Sast & Code Quality Findings

Recreating a Code Quality and a SAST Finding on the same line is not impossible but rather unusual so we have to mock this data a little

1. Clone this Project into your GDK
2. Recreate this MR
3. apply the attached patch below to mock SAST findings
4. hover over line 17

diff --git a/app/assets/javascripts/diffs/index.js b/app/assets/javascripts/diffs/index.js
index 3b84d9c6ac4d..89942105c4d0 100644
--- a/app/assets/javascripts/diffs/index.js
+++ b/app/assets/javascripts/diffs/index.js
@@ -38,7 +38,7 @@ export default function initDiffsApp(store = notesStore) {
         endpointDiffForPath: dataset.endpointDiffForPath || '',
         endpointCoverage: dataset.endpointCoverage || '',
         endpointCodequality: dataset.endpointCodequality || '',
-        endpointSast: dataset.endpointSast || '',
+        endpointSast: dataset.endpointSast || 'mockedEndpoint',
         endpointUpdateUser: dataset.updateCurrentUserPath,
         projectPath: dataset.projectPath,
         helpPagePath: dataset.helpPagePath,
diff --git a/ee/app/assets/javascripts/diffs/store/actions.js b/ee/app/assets/javascripts/diffs/store/actions.js
index 3c91c1fc3482..8f0c61f529bb 100644
--- a/ee/app/assets/javascripts/diffs/store/actions.js
+++ b/ee/app/assets/javascripts/diffs/store/actions.js
@@ -100,50 +100,19 @@ export const setGenerateTestFilePath = ({ commit }, path) =>
   commit(types.SET_GENERATE_TEST_FILE_PATH, path);
 
 export const fetchSast = ({ commit, state, dispatch }) => {
-  let retryCount = 0;
-  sastPoll = new Poll({
-    resource: {
-      getSastDiffReports: (endpoint) => axios.get(endpoint),
-    },
-    data: state.endpointSast,
-    method: 'getSastDiffReports',
-    successCallback: ({ status, data }) => {
-      retryCount = 0;
-      if (status === HTTP_STATUS_OK) {
-        commit(types.SET_SAST_DATA, data);
-        dispatch('stopSastPolling');
-      }
-    },
-    errorCallback: ({ response }) => {
-      if (response.status === HTTP_STATUS_BAD_REQUEST) {
-        // we could get a 400 status response temporarily during report processing
-        // so we retry up to MAX_RETRIES times in case the reports are on their way
-        // and stop polling if we get 400s consistently
-        if (retryCount < MAX_RETRIES) {
-          sastPoll.makeDelayedRequest(RETRY_DELAY);
-          retryCount += 1;
-        } else {
-          sastPoll.stop();
-        }
-      } else {
-        retryCount = 0;
-        dispatch('stopSastPolling');
-        createAlert({
-          message: __('An unexpected error occurred while loading the Sast diff.'),
-        });
-      }
-    },
-  });
-
-  if (!Visibility.hidden()) {
-    sastPoll.makeRequest();
-  }
-
-  Visibility.change(() => {
-    if (!Visibility.hidden()) {
-      dispatch('restartSastPolling');
-    } else {
-      dispatch('stopSastPolling');
-    }
+  commit(types.SET_SAST_DATA, {
+    added: [
+      {
+        severity: 'high',
+
+        description:
+          'Markup escaping disabled. This can be used with some template engines to escape\ndisabling of HTML entities, which can lead to XSS attacks.\n',
+        location: {
+          file: 'noise.rb',
+          start_line: 7,
+        },
+      },
+    ],
+    fixed: [],
   });
 };

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.